Mexican Breakfast Casserole
Published January 6, 2024 • Updated July 20, 2026
This post may contain affiliate links. See my disclosure policy.
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.
Explore hundreds of keto recipe videos with step-by-step instructions, tips, and tricks to make keto easy.
Ingredients
1 tablespoon avocado oil -
1 lb ground pork or Italian sausage
-
1/2 medium onion, chopped
-
1/2 green bell pepper, chopped
-
2 teaspoon chili powder
-
1 teaspoon garlic powder
-
1/2 teaspoon ground cumin
-
10 oz can diced tomatoes & green chiles (Rotel)
-
8 low-carb flour tortillas
-
3 cups shredded Mexican blend cheese
-
6 eggs
-
1 ½ cups milk of choice
-
1/2 cup heavy whipping cream
-
3/4 teaspoon salt
-
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.
Your Macros. Your Recipes. Calculated in 60 Seconds.
Get personalized keto macros and instantly see which recipes fit your targets. No more guessing what to eat.
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.
Three months into keto and I thought Mexican breakfast was gone forever. The night-before custard prep is what finally got me to try it, no way I'm doing an hour of cooking on a Tuesday morning. The sausage and Rotel base is honestly worth it alone. Still figuring out my chili powder amount.
Two teaspoons is where I land but chili powder varies a lot by brand. I'd taste the sausage layer before assembly and adjust there, it's the easiest point to fix it.
Good catch before everything piles on. I'll try 2 teaspoons next time.
The smell pulled my son out of his room before I called anyone for breakfast. He wanted to know if it was the cumin. It was.
Eight servings at under 5 net carbs each and I was full till early afternoon, which almost nothing on keto does for me at breakfast. Went low-carb about a year ago and weekends lost their breakfast thing pretty fast. Eggs are fine but they're not a casserole you pull out of the oven to actual excitement.nnFilling holds better if you refrigerate it overnight before baking, the tortillas absorb the custard and the whole thing slices cleaner. Something about the sausage and bell pepper in that spice blend smells exactly like Saturday mornings used to. First time in a while breakfast felt worth making again.
Dan, the Saturday morning smell is the whole thing with this one. Same as me. Custard distributes better, slices cleaner.
Simmering the Rotel down first is what every other recipe skips. No soggy base, no falling-apart servings. This is the one I use now.
Freeze well? First time making it and nailed it.
The cheese pull when you use pepper jack though.
Tanya, I haven't tried it that way yet but now I want to. Pepper jack against the cumin and chili powder already in there? Yeah, that tracks.
Heading back to the store for the green pepper because yeah, not optional. Batch eight probably.
Ashley, batch eight and still making store runs for it. The green pepper is doing something in that sausage layer that the onion can't replicate. I keep a spare on hand now.
Was sweating the egg custard the whole time (first casserole I've ever attempted), but it pulled through and that Rotel heat is totally worth it. Mine ran a little greasy on top, probably didn't drain the sausage fat well enough. Do you use the full can of Rotel liquid or drain some before adding?
Full can goes in, but I cook it down until the liquid's almost completely gone. The grease thing, you called it. Blotting with paper towels after draining helps when the sausage runs fatty.
Made this Sunday before a pool day. Needed something substantial but didn't want to stand over the stove. My youngest, who picks apart every breakfast casserole I've ever made looking for 'the weird bits,' ate two full portions and asked me point-blank if I used real tortillas. Said everything. Four stars only because I'd go with hot Rotel next time; the mild version didn't bring enough heat. But the cumin in the egg custard is what makes this feel like a proper breakfast, not just scrambled eggs in a pan.
Hot Rotel next time, yes. I always go mild because half the people making this are feeding kids who don't do heat, but if you know your crowd, go hot. Two portions from the one who picks apart every casserole is a better review than four stars.
Tried probably four or five keto breakfast casseroles over the past year and this one actually stuck. The Rotel in the egg custard cuts through the cheese in a way the others don't, keeps it from feeling heavy. Not perfect (I'd add a little more chili powder next time), but it's the version I'll keep coming back to.
More chili powder is the right call. I go closer to a tablespoon when I want it to actually register.
Tried a few other keto breakfast casseroles over the past year and the egg-to-filling ratio always felt off. This one layers differently, the tortillas hold everything together instead of just disappearing into the custard. It actually tastes like a breakfast casserole.
The tortilla thing is load-bearing. I layered them specifically so the custard wouldn't just pool at the bottom. Glad it reads that way.
I almost skipped this because I've had bad luck with low-carb tortillas going gummy in casseroles, but layering them with the Rotel mixture kept everything from getting soggy. The cumin in the egg custard is subtle but it pulls the whole thing together in a way I didn't anticipate. Making a double batch for Mother's Day brunch.
Diane, that cumin fades into the background but without it, you'll notice something's off even if you can't name it. Learned that the hard way. And yes, double batch! This holds overnight so mornings you're just pulling from the fridge.
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.
Chorizo is my go-to swap here too. I pull more fat off after browning since it renders harder than pork, but the depth it adds to the custard is worth it. Smart move on the chili powder.
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.
Yeah, it gets better as the week goes on. If you ever want to stretch it past day 5, I freeze the last few slices in parchment then foil, reheat straight from frozen, still not rubbery.
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.
The cumin thing is real. Day two is my favorite serving too. On the tortillas, if you reheat uncovered for the last 30 seconds it crisps them back up a little.