Mexican Ground Beef Casserole

This cheesy Mexican ground beef casserole is filled with tomatoes, peppers and black beans and features a low-carb twist using cauliflower rice. It’s a 40-minute meal packed with big flavors that everyone will love and an easy weeknight win.

With a block of cheese in the fridge and a packet of taco seasoning in the cabinet, this is the kind of Tex-Mex meal you can whip up almost any night. It uses fridge and pantry basics to create a cozy, comforting casserole that’s veggie-packed and filling.

If you’ve made and loved our Mexican ground beef skillet recipe, this casserole will be a fast favorite. The two recipes are quite similar, but that one is made stove-top in a pan and this one comes together in a casserole dish in the oven.

I also love the low-carb approach this Mexican casserole takes by using cauliflower rice instead of real rice. It’s an easy way to get in extra vegetables and fiber while still indulging in a casserole.

Here’s Why I Love It

• You can change the fillings based on what you have on hand. Like any good casserole, it’s flexible and adaptable.
• Swapping out the protein makes it accessible to whatever you have in the freezer. Use ground chicken, turkey, lamb or bison.
• It’s a great clean out the fridge and pantry type of meal.
• Taco seasoning packets keep the ingredient list simple but still bring big flavor.

What You’ll Need

There are a lot of basic pantry, fridge and freezer items in this ground beef Mexican casserole and very limited prep work.

Ground beef — I like to use an 85/15 blend. The fat gives this casserole extra flavor. Grass-fed beef is a good choice when using fattier blends.

Onion & garlic — Use fresh onions and garlic if you can, but in a pinch ground spices will work too.

Bell pepper — This can be any color bell pepper but I’m partial to red peppers for their sweeter taste.

Diced tomatoes & tomato paste — You can drain the diced tomatoes to limit the excess liquid in the casserole. The tomato paste adds great depth of flavor.

Black beans — Another bean variety such as pinto would work fine too.

Cauliflower rice — Instead of regular rice, cauliflower rice is used for a lower carb option. You can swap out regular cooked rice if you prefer.

Taco seasoning — This is one of my favorite quick hacks for quick Tex-Mex flavor instead of needing to open 5 different spice jars. It brings plenty of flavor to the casserole with convenience.

Cheddar cheese — Shred this yourself instead of opting for pre-shredded cheese. It just doesn’t melt the same. Other good options include a Mexican blend, Colby Jack, Monterey Jack or even queso fresco.

Cilantro — This is the herb that brings any and all Mexican dishes together. It’s bright freshness is exactly what this savory casserole needs before serving.

How To Make The Casserole

This dish of cheesy comfort can be on your table in 40 minutes. Here’s the rundown of how to do it, but check out the full recipe down below.

Start by browning the beef, onion, garlic and bell pepper in a skillet with olive oil over medium heat.

My Pro Tip

Recipe Tip

Depending on how much fat your ground beef has, you may want to drain the skillet after browning.

After about 3-5 minutes, when the beef is browned, add the cauliflower rice, diced tomatoes, tomato paste, black beans, taco seasoning and cilantro. Stir everything together and cook for a minute or two until heated through.

Transfer the mixture to a prepared 9″x13″ casserole dish. Sprinkle the freshly grated cheddar cheese on top and bake at 400°F for about 25 minutes until the cheesy is melted and bubbly.

Remove the casserole dish from the oven. Let it rest for a few minutes then garnish with more cilantro before serving.

Other Ideas, Substitutions and Tips!

• This casserole will remind you of a stuffed pepper filling and it could easily work as that too. If you want a way to repurpose this recipe, try it in stuffed peppers.
• Serve the casserole with broken tortilla chips on top for some crunch and added Mexican flair.
• As mentioned above, use real rice instead of cauliflower rice. The result will be a creamier casserole consistency as the rice will soak up the liquid. If you do this and are using uncooked rice, don’t drain the diced tomatoes and add a bit of beef broth to the casserole dish before baking. Quinoa is another grain option instead of cauliflower rice. Check out this cheddar chicken bake if you enjoy cooking with quinoa.
• Other serving options include sliced avocado, chopped green onions, sliced olives and sour cream (or Greek yogurt). A squeeze of fresh lime before serving is also a nice balance to the savory Mexican flavors.
• For a more indulgent casserole, add a layer of the green sauce from espagueti verde before baking.
• If you’re a spice lover, throw in some sliced jalapeños along with the bell peppers or use a can of diced green chiles in the recipe.

More Mexican-Inspired Recipes To Try

• Mexican vegetable soup is another quick and easy recipe that comes together in one-pot.
• If you’re on the lookout for a slow cooker recipe, nothing beats this shredded Mexican beef. It’s so flavorful and perfect for meal prepping.
• Instead of stuffing peppers, how about stuffed Mexican onions? These are fun twist to the usual stuffed vegetables and the filling is once again comforting and delicious.
• For another Mexican casserole recipe, try this cheese enchiladas casserole or our baked salsa verde chicken.