This keto Mexican breakfast casserole bakes up rich and cheesy, layering low-carb tortillas with seasoned sausage, Rotel, and a cumin-spiced egg custard I prep the night before, with 4.9g net carbs and 31.8g protein per serving.
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 minimum, 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.
My favorite swaps
I’ve made this dozens of ways over the years. Here’s what I keep going back to.
Protein swaps (chorizo is my favorite)
Chorizo is the best swap I’ve found. It adds smoky, spicy flavor that matches the cumin and chili powder already in the dish. I brown it the same way, but I drain more fat since chorizo renders a lot. Cooked bacon (chopped), ground turkey, and ground chicken all work too. Turkey and chicken need extra seasoning since they’re leaner. I add an extra half teaspoon of chili powder when I use either one.
Vegetable swaps
I’ve subbed in fresh tomatoes, sliced mushrooms, chopped spinach, diced zucchini, and black olives at various points. Mushrooms and spinach are my go-to swaps because they don’t release as much water as tomatoes. If you use fresh tomatoes, dice them small and pat dry first.
Make it vegetarian
Skip the sausage and load up on vegetables. For keto-friendly protein, I use black soy beans instead of regular black beans. They have a fraction of the carbs and hold up in the egg custard.
Dairy-free version
I’ve tested this with unsweetened almond milk and macadamia nut milk in the egg mixture. Both work. The custard sets slightly thinner but the flavor barely changes. Skip the cheese or use a vegan shred that melts.
Make ahead, freeze, and reheat
Make ahead
I assemble everything through the egg pour, cover the dish with foil, and refrigerate. Three hours is my minimum soak time, but overnight works perfectly. Bake the next morning at 350°F for 50-60 minutes. Add 5-10 extra minutes if it’s coming straight from the fridge.
How to freeze
I freeze this two ways. For the unbaked version, assemble the layers and cheese but don’t add the egg mixture yet. Cover tightly with plastic wrap and foil, then freeze for up to 3 months. Thaw overnight in the fridge, pour the eggs over, and bake as directed.
For individual slices (my preferred method), bake the full casserole first, let it cool completely, then cut into portions. I wrap each slice in parchment, then foil, and freeze. Reheat straight from frozen in the air fryer at 325°F for 5-6 minutes. This is the grab-and-go version I rely on for busy mornings.
Reheating
Air fryer: 325°F for 3-4 minutes from the fridge, or 5-6 minutes from frozen. Microwave: 60-90 seconds on a plate. I prefer the air fryer because the edges crisp back up.
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.
Preheat oven to 350°F and spray a casserole dish with cooking spray. Set aside.
2
Cook sausage
To a large skillet, heat oil over medium-high heat. Add ground sausage and brown until cooked through.
For this step
1 tablespoon avocado oil
1 lb ground pork or Italian sausage
3
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.
For this step
1/2 medium onion, chopped
1/2 green bell pepper, chopped
2 teaspoon chili powder
1 teaspoon garlic powder
1/2 teaspoon ground cumin
4
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.
For this step
10 oz can diced tomatoes & green chiles
5
Cut tortillas
Cut each tortilla in half down the center.
For this step
8 low-carb flour tortillas
6
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.
For this step
3 cups shredded Mexican blend cheese
7
Add egg mixture
In a medium bowl, whisk together eggs, milk, heavy cream, salt & pepper. Pour egg mixture over the casserole.
For this step
6 eggs
1 ½ cups milk of choice
1/2 cup heavy cream
3/4 teaspoon salt
1/2 teaspoon black pepper
8
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
Per serving: 1/8 of recipe
Calories
533
Fat
41.1g
Protein
31.8g
Total carbs
22g
Net carbs
4.9g
Nutrition is an estimate calculated from the ingredients listed. Brands vary, so check labels if you track closely.
Frequently Asked Questions
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.
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.
Hi Annie! I have been following you forever and your breakfast recipes are my favorites. I made this yesterday morning and there was none left by dinner!!
I made a full pan of this for a Sunday brunch potluck at my neighbor’s, mostly because I could do the custard the night before and not be scrambling in the morning, and when I set it out warm the Rotel smell hit first before anyone even had a plate. Mine cleared faster than the regular egg bake on the other end of the table. Two people were convinced there was chorizo in it from the spice, and when I said it was Italian sausage and chili powder they looked skeptical. Going double batch next time.
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.
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.
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.
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.
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.
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.
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.
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.
The Rotel is actually what keeps them from going soggy, it’s thick enough that it doesn’t oversaturate the layers. Three hours ahead is my sweet spot but overnight works fine too.
