Mexican Breakfast Casserole
Published January 6, 2024 • Updated February 28, 2026
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This keto Mexican breakfast casserole layers low-carb tortillas with seasoned sausage, Rotel, and cheese, all held together by a cumin-spiced egg custard I prep the night before.
My sausage breakfast casserole is the reason I started building layered egg bakes, but this Southwest version is the one I come back to most. I prep it the night before, slide it in the oven the next morning, and my family gets a hot, protein-packed breakfast without me standing over a stove at 7 AM.
The key is how I build the layers. I cook ground sausage with onions and peppers, add a full can of Rotel, then simmer until all the liquid cooks off. That step matters more than anything else in this recipe. If you pour wet filling over tortillas, they fall apart. Once the Rotel reduces, it becomes this thick, concentrated layer that adds heat without the moisture that makes casseroles soggy. I sandwich tortilla halves between the sausage mixture and shredded Mexican cheese, pour a cumin-spiced egg custard over the top, and let the whole thing soak. Three hours ahead is my sweet spot, but overnight works fine too.
The seasoning is what makes this a true Southwest egg bake. Chili powder, cumin, and garlic go directly into the sausage, so every bite carries that smoky warmth. I skip salsa on purpose because it waterlogged the casserole the two times I tried it, especially on day two. Rotel plus dry spices gives you the same flavor without the sogginess.
Why this is the one I keep making
- Keto-friendly layers. I use zero net carb tortillas that hold their structure even after soaking overnight. The whole dish stays high protein and low carb without tasting like diet food.
- Southwest seasoning baked in. Cumin, chili powder, and garlic cook into the sausage so the flavor is in every layer, not sitting on top as a garnish.
- Make-ahead for real. I assemble this the night before and bake at 350 the next morning. My keto quiche and ham frittata are great for mornings too, but neither preps this far ahead.
- Feeds a crowd. Eight generous slices. I bring this to brunch at friends’ houses and serve it alongside breakfast bowls when I want variety on the table.
If you’re stocking your freezer with breakfast quesadillas and other grab-and-go options, this casserole freezes well in individual slices too. I wrap each piece in parchment then foil and reheat straight from frozen in the air fryer. It’s become part of my weekly breakfast rotation alongside sausage cheddar biscuits.
How to make a Mexican breakfast casserole?
I build this in layers, and the whole thing comes together in about 20 minutes of active work.
- Brown the sausage, then cook down the onions and peppers.
- Season with chili powder, cumin, and garlic, then stir in Rotel and simmer until the liquid cooks off.
- Whisk the eggs with milk and cream.
- Layer tortilla halves, sausage mixture, and cheese in the baking dish. Repeat once.
- Pour the egg mixture over everything.
- Bake at 350 for 50-60 minutes until the center is set.
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Ingredients
1 tablespoon avocado oil -
1 lb ground pork or Italian sausage
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1/2 medium onion, chopped
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1/2 green bell pepper, chopped
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2 teaspoon chili powder
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1 teaspoon garlic powder
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1/2 teaspoon ground cumin
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10 oz can diced tomatoes & green chiles (Rotel)
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8 low-carb flour tortillas
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3 cups shredded Mexican blend cheese
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6 eggs
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1 ½ cups milk of choice
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1/2 cup heavy whipping cream
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3/4 teaspoon salt
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1/2 teaspoon black pepper
Step by Step Instructions
Step by Step Instructions
Preheat oven
Preheat oven to 350°F and spray a casserole dish with cooking spray. Set aside.
Cook sausage
To a large skillet, heat oil over medium-high heat. Add ground sausage and brown until cooked through.
- 1 tablespoon avocado oil
- 1 lb ground pork or Italian sausage
Add vegetables and seasoning
Add chopped onion and green pepper to the skillet with the cooked sausage. Sauté until softened. Stir in seasonings – chili powder, garlic powder, cumin.
- 1/2 medium onion, chopped
- 1/2 green bell pepper, chopped
- 2 teaspoon chili powder
- 1 teaspoon garlic powder
- 1/2 teaspoon ground cumin
Add Rotel
Stir in diced tomatoes with green chiles. Let simmer for 10 minutes or until the liquid from the tomatoes has cooked off. Remove skillet from the heat.
- 10 oz can diced tomatoes & green chiles
Cut tortillas
Cut each tortilla in half down the center.
- 8 low-carb flour tortillas
Assemble
To the prepared baking dish, layer down half of the tortilla halves. Top tortillas with half of the sausage mixture. Sprinkle on half the shredded cheese. Repeat layers one time.
- 3 cups shredded Mexican blend cheese
Add egg mixture
In a medium bowl, whisk together eggs, milk, heavy cream, salt & pepper. Pour egg mixture over the casserole.
- 6 eggs
- 1 ½ cups milk of choice
- 1/2 cup heavy cream
- 3/4 teaspoon salt
- 1/2 teaspoon black pepper
Bake
Cover baking dish with aluminum foil and bake at 350°F for 50-60 minutes or until the center is cooked through and no longer jiggly on top.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
Why don't the tortillas get soggy?
I simmer the Rotel until all the liquid cooks off before assembly. That's the step that makes or breaks this dish. Once the tomato mixture reduces into a thick paste, it adds flavor without waterlogging the tortillas. I also sandwich the tortilla halves between protein layers and cheese, so they're sealed on both sides. Reader Riley K. confirmed this: she was sure the tortillas would get soggy and they held up completely.
Can I use corn tortillas?
I skip corn tortillas for keto since they're around 10g net carbs each. I use zero net carb flour tortillas instead, and they hold their structure in the egg custard even after an overnight soak. If you have a favorite low-carb tortilla brand, it should work fine here.
Can I assemble this the night before?
I do this almost every time. I assemble the whole casserole through the egg pour, cover it with foil, and refrigerate. Three hours ahead is my minimum, but overnight works just as well. The longer soak actually helps the egg custard absorb into the layers more evenly. If you want another make-ahead breakfast option, my french toast casserole preps the same way.
Can I freeze individual slices?
I freeze slices all the time. I bake the full casserole, let it cool completely, then cut into portions. I wrap each slice in parchment, then foil, and freeze for up to 3 months. Reheat straight from frozen in the air fryer at 325°F for 5-6 minutes. The parchment layer keeps the foil from sticking.
What protein works instead of sausage?
I've tested chorizo, bacon, ground turkey, and ground chicken in this. Chorizo is my favorite swap because it matches the cumin and chili powder already in the recipe. I brown it the same way but drain more fat since chorizo renders a lot. If you go with turkey or chicken, add an extra half teaspoon of chili powder since lean proteins absorb less flavor.
How do I know when the center is done?
I check at 50 minutes. Give the dish a gentle shake. If the center jiggles like set pudding, it's done. If it sloshes like liquid, it needs more time. I usually end up at 55 minutes, but ovens vary. The edges will be slightly puffed and pulling away from the dish when it's ready. Let it rest 10 minutes before slicing so the layers hold together.
How can I make this even lower in carbs?
I reduce or skip the bell pepper and onion when I want fewer carbs. The Rotel and dry spices carry enough flavor on their own. If your tortillas have any net carbs, switching to a zero carb brand makes the biggest difference. I've also made this without tortillas entirely (just sausage, egg custard, and cheese layered in the dish), and it works as a crustless version.
I use chorizo instead of Italian sausage and skip the extra chili powder since chorizo already has the heat. The fat renders into the egg layer and you get a deeper, spicier flavor throughout. Worth the swap if you can find it.
Made a double batch on Sunday and I'm still pulling portions out every morning. The egg custard holds together way better reheated than I expected, not rubbery at all (actually better on day two). This is going in every weekly meal prep from now on.
Been using this as my Sunday meal prep for about a month. Made the full 8-serving batch, portioned into containers, and it reheats fine straight from the fridge covered for 3 minutes. The cumin in the egg custard actually deepens after a day, so Tuesday's portion tastes noticeably better than Sunday's. One thing to know: the tortillas soften a lot by day three, so eat it within the first two days if you want that layered texture.
I've made this probably six times now and the egg custard with the cumin is the part I keep coming back for (I almost want to eat it before it goes in the oven). The tortillas soak up everything overnight and then set into these soft, savory layers and it's freaking unbelievably good every single time. I've tried other breakfast casseroles but nothing hits like this one does. Starting to double the batch.
Six times and still trying not to eat the custard raw first. I sneak in an extra half teaspoon of cumin. Kicks it up without being obvious about it.
Third time making this and I finally tried chorizo instead of Italian sausage. Fat renders different, the whole thing turns this deep reddish color. The overnight egg custard soak hits even harder with that smoky heat. Not going back.
Mine went that same deep color the first time I made it with chorizo. The fat works into the egg custard overnight in a way it just doesn't when you cook and serve same day. Yeah, no going back.
Swapped in chorizo for the Italian sausage and skipped the extra spice (the chorizo handles it). The fat rendered into the egg custard and made the whole thing way richer than I expected. Worth noting: prep it the night before. Tried it same-day once and the layers didn't hold nearly as well.
Chorizo fat renders totally different. I drain more than I do with Italian sausage but leave enough in that it soaks into the egg custard overnight. That's where the richness comes from.
Made this for a brunch last weekend and a friend who came in saying she'd already eaten ended up with a full plate. The cumin in the egg custard is what pulled everyone in (the smell when you lift the foil is something else). I'd go with a spicier sausage next time, but that's personal taste, not a flaw.
Almost pulled the cumin. Glad I didn't. Double batch next time. Slices freeze well.
My mom made a breakfast casserole like this every Sunday morning when I was growing up, flour tortillas and all. It's the smell I remember most, cumin and sausage coming through the oven while everyone scrambled to get ready. I spent years after starting keto trying to recreate it and nothing quite landed until I found this recipe. The Rotel is what does it. That bright tomato-chile flavor cuts through the egg custard in a way I wasn't expecting. Made it last weekend and the first bite just stopped me. Pulled it from the oven Sunday morning and it felt like being back in that kitchen. This is the one.
The Rotel has to cook completely dry or the tortillas get soggy. Once it reduces it goes almost jammy and the tomato-chile flavor concentrates. That Sunday morning smell is real.
Do the low-carb tortillas get soggy if you assemble it the night before? Making this for Sunday brunch and really don't want to be scrambling last minute.
That's how I always do it. Overnight actually gives the egg custard more time to soak in, so it slices way cleaner than same-day.
I almost skipped this because I couldn't picture low-carb tortillas surviving an overnight soak in egg custard without turning to complete mush. Made it Sunday morning and pulled it out of the oven with my jaw on the floor. The layers held up, the Rotel cut right through all that sausage fat, and the cumin in the custard did something I did not expect. Next time I'm doubling it.
Almost pulled the cumin from my test batch. Kept second-guessing it. Double batch is worth it, slices freeze well.
Drain the Rotel. I cannot emphasize this enough. First time I made this the bottom layer was borderline soggy and I couldn't figure out why until I realized I'd dumped the whole can liquid and all into the sausage mixture. Second batch I strained it and pressed the filling down into the tortilla layers instead of just spooning it on, and it came out completely different. Still not a five-star for me because the bottom tortillas do soften a little no matter what, but for something I can prep Sunday night and eat through Wednesday, this is where I keep landing.
The liquid is the whole thing with Rotel. I simmer mine down until it looks almost jammy before layering it in. Draining works too, just faster. Bottom tortillas softening is just what happens with this one.
Made this Sunday and it came out really well for someone who doesn't cook much. The cumin in the egg custard surprised me (I almost skipped it because I didn't think it would matter) but it's actually what pulls everything together. My one note is the green bell pepper felt a little mild for a Mexican dish, I think I'd swap it for jalapeño next time to get some actual heat in there. But the base is solid and I'm making it again.
Jalapeño swap makes sense. Green pepper is mostly there for texture, not heat. Same prep, just more kick.
Brought this to a neighborhood brunch last weekend and made a double batch to be safe. Watched a woman go back three times and finally ask what was in it because she said it tasted like something her mom used to make. (She was not on keto.) The Rotel and cumin together, that's what does it. Already have it on the list for Easter morning.
'Not on keto' is always the best part of those stories. Make it the night before for Easter, the overnight soak just makes it better.
Went in fully expecting the low-carb tortillas to just dissolve overnight. They didn't. The Rotel cuts through all that richness in a way I wasn't ready for.
The Rotel has to cook completely down before you layer it. Nothing left in the pan. That's what keeps the tortillas intact overnight, but all that acid is still there to cut through the cheese and custard.
My grandma made something like this every Christmas morning. Thought I'd never have it again, but the Rotel and cumin brought it all back.
Those two together hit a very specific note. Glad it brought it back.