Cheesy Mexican Ground Beef Casserole

I’ll be honest—casseroles used to remind me of those heavy, overly-complicated dishes that took forever to make and left me with a sink full of dishes. Then I discovered the magic of one-dish meals that actually taste good and don’t require a culinary degree.

This Mexican ground beef casserole changed my mind about the whole thing. It’s got all the flavors of taco night—seasoned beef, melted cheddar, black beans—but it comes together in one pan. No multiple pots, no complicated steps, just layer everything in and let the oven do the work. Plus, I sneak cauliflower rice in there, so I can pretend it’s somewhat healthy while my family devours it without even noticing.

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What Kind of Ground Beef Should I Use?

For this casserole, you’ll want to pick ground beef with a fat content that balances flavor and moisture without making your dish too greasy. I typically go with 85/15 ground beef, which gives you enough fat for good taste while still being lean enough that you won’t need to drain off tons of grease. If you prefer something leaner, 90/10 will work just fine, though your casserole might be slightly less juicy. You can also swap in ground turkey or ground chicken if that’s what you have on hand, just know that you might want to add a touch more oil since those meats are naturally leaner.

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Options for Substitutions

This casserole is easy to customize based on what you have in your kitchen:

• Ground beef: Ground turkey, chicken, or pork work great here. You can also use plant-based ground meat if you prefer a vegetarian option.
• Cauliflower rice: Not a fan of cauliflower rice? Regular cooked white or brown rice makes a perfect swap. Use about 1 ½ cups of cooked rice instead. You can also try quinoa for extra protein.
• Black beans: Pinto beans, kidney beans, or even corn work just as well. Canned beans are convenient, but make sure to drain and rinse them first.
• Red bell pepper: Any color bell pepper works fine – green, yellow, or orange. You could also use poblano peppers for a slightly smoky flavor.
• Cheddar cheese: Monterey Jack, pepper jack, or a Mexican cheese blend are all good alternatives. For extra flavor, try mixing two types of cheese together.
• Taco seasoning: If you don’t have store-bought taco seasoning, make your own with 1 tablespoon chili powder, 1 teaspoon cumin, ½ teaspoon paprika, and a pinch of cayenne pepper.

Watch Out for These Mistakes While Cooking

The biggest mistake when making this casserole is not draining the ground beef after browning, which leaves you with a greasy, watery dish – take an extra minute to drain off the excess fat before adding your vegetables.

Another common error is forgetting to drain the canned diced tomatoes and black beans, as that extra liquid will make your casserole soupy instead of thick and hearty.

To get the best flavor, make sure your beef is actually browned with some caramelization rather than just gray and steamed, which means avoid overcrowding the pan and let it sit undisturbed for a minute or two.

Finally, don’t skip seasoning with salt and pepper after adding all the ingredients – the taco seasoning alone won’t be enough to bring out all the flavors, so taste and adjust before transferring to your baking dish.

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What to Serve With Mexican Ground Beef Casserole?

This casserole is pretty hearty on its own, but I love serving it with a dollop of sour cream and some fresh guacamole on top. A simple side salad with romaine lettuce, cherry tomatoes, and a lime vinaigrette helps balance out the richness of all that melted cheese. Tortilla chips are always a good call for scooping up extra bites, or you could warm up some flour tortillas on the side. If you want to make it a bigger meal, Spanish rice or cilantro lime rice pairs really nicely with the Mexican flavors in the casserole.

Storage Instructions

Store: This casserole is a great make-ahead meal that keeps really well in the fridge. Just let it cool completely, then cover tightly with foil or transfer to an airtight container for up to 4 days. It actually tastes even better the next day once all the flavors have had time to hang out together!

Freeze: You can definitely freeze this casserole for busy weeknights. Either freeze the whole thing in the baking dish wrapped tightly in plastic wrap and foil, or portion it out into individual servings. It’ll stay good in the freezer for up to 3 months.

Reheat: To warm it up, cover with foil and bake at 350°F for about 20-25 minutes if coming from the fridge, or 35-40 minutes from frozen. You can also microwave individual portions for 2-3 minutes, stirring halfway through. Add a little extra cheese on top if you want to freshen it up!

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 2050-2250
• Protein: 110-130 g
• Fat: 120-135 g
• Carbohydrates: 80-95 g

Ingredients

For the casserole:

• 3 tbsp olive oil (I use California Olive Ranch extra virgin olive oil)
• 1 lb ground beef
• 1 small onion
• 2 garlic cloves
• 1 red bell pepper
• 2 cups cauliflower rice
• 14 oz diced tomatoes
• 2 tbsp tomato paste
• 2 tbsp cilantro
• 3 tbsp taco seasoning
• 1 tsp ground cumin
• 1 cup black beans
• salt to taste
• black pepper to taste

For the topping:

• 2.5 cups cheddar cheese

Step 1: Prepare Mise en Place and Preheat Oven

• 1 small onion, diced
• 2 garlic cloves, minced
• 1 red bell pepper, diced
• 3 tbsp taco seasoning
• 1 tsp ground cumin
• 2 tbsp cilantro
• 14 oz diced tomatoes
• 2 tbsp tomato paste
• 1 cup black beans

Preheat your oven to 400°F and lightly grease a 9×13 inch baking dish.

While the oven heats, dice the small onion into small pieces, mince the 2 garlic cloves, and dice the red bell pepper.

Measure out the taco seasoning, cumin, cilantro, and have the diced tomatoes, tomato paste, and black beans ready nearby.

This prep work ensures everything moves smoothly once you start cooking.

Step 2: Brown the Beef with Aromatics

• 3 tbsp olive oil
• 1 lb ground beef
• diced onion, garlic, and bell pepper from Step 1

Heat 3 tablespoons of olive oil in a large skillet over medium-high heat.

Add the ground beef and cook for 2-3 minutes, breaking it up with a spoon as it cooks.

Once the beef is mostly browned, add the diced onion, minced garlic, and diced bell pepper.

Continue cooking for another 2 minutes, stirring occasionally, until the vegetables are slightly softened and the garlic becomes fragrant.

This builds a flavorful foundation for your casserole.

Step 3: Build the Casserole Base

• 2 cups cauliflower rice
• beef and vegetable mixture from Step 2
• 14 oz diced tomatoes
• 2 tbsp tomato paste
• 3 tbsp taco seasoning
• 1 tsp ground cumin
• 1 cup black beans
• salt to taste
• black pepper to taste

Add the 2 cups of cauliflower rice to the skillet and stir well to combine with the beef mixture.

Cook for 1 minute to slightly soften the rice.

Pour in the diced tomatoes and tomato paste, then add the taco seasoning, ground cumin, and black beans.

Stir everything together until well combined and the tomato paste is fully incorporated.

I like to taste the mixture at this point and adjust the salt and pepper to your preference—sometimes the taco seasoning varies in saltiness between brands, so it’s better to check before baking.

Step 4: Assemble and Top with Cheese

• beef and vegetable mixture from Step 3
• 2.5 cups cheddar cheese

Transfer the entire beef and vegetable mixture from the skillet into your prepared baking dish, spreading it evenly.

Sprinkle the 2.5 cups of shredded cheddar cheese evenly over the top, making sure to cover most of the surface—this helps it melt uniformly and creates a golden, bubbly top.

Step 5: Bake Until Cheese is Melted and Bubbly

Place the baking dish in the preheated 400°F oven and bake for 20-25 minutes, until the cheese is fully melted and the edges of the casserole are bubbling.

The cooking time may vary slightly depending on your oven, so start checking around the 20-minute mark.

I prefer to pull it out when the cheese has just turned golden at the edges—it gives the casserole better texture than pulling it out earlier.

Step 6: Finish and Serve

• 2 tbsp cilantro, fresh

Remove the casserole from the oven and let it rest for 2-3 minutes before serving.

Garnish with the fresh cilantro right before serving for a bright pop of color and flavor that cuts through the richness of the cheese.

Cheesy Mexican Ground Beef Casserole

Delicious Cheesy Mexican Ground Beef Casserole recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 25 minutes mins

Total Time 40 minutes mins

Servings 6 servings

Calories 2150 kcal

Ingredients

  

For the casserole::

• 3 tbsp olive oil (I use California Olive Ranch extra virgin olive oil)
• 1 lb ground beef
• 1 small onion
• 2 garlic cloves
• 1 red bell pepper
• 2 cups cauliflower rice
• 14 oz diced tomatoes
• 2 tbsp tomato paste
• 2 tbsp cilantro
• 3 tbsp taco seasoning
• 1 tsp ground cumin
• 1 cup black beans
• salt to taste
• black pepper to taste

For the topping::

• 2.5 cups cheddar cheese

Instructions

 

• Preheat your oven to 400°F and lightly grease a 9x13 inch baking dish. While the oven heats, dice the small onion into small pieces, mince the 2 garlic cloves, and dice the red bell pepper. Measure out the taco seasoning, cumin, cilantro, and have the diced tomatoes, tomato paste, and black beans ready nearby. This prep work ensures everything moves smoothly once you start cooking.
• Heat 3 tablespoons of olive oil in a large skillet over medium-high heat. Add the ground beef and cook for 2-3 minutes, breaking it up with a spoon as it cooks. Once the beef is mostly browned, add the diced onion, minced garlic, and diced bell pepper. Continue cooking for another 2 minutes, stirring occasionally, until the vegetables are slightly softened and the garlic becomes fragrant. This builds a flavorful foundation for your casserole.
• Add the 2 cups of cauliflower rice to the skillet and stir well to combine with the beef mixture. Cook for 1 minute to slightly soften the rice. Pour in the diced tomatoes and tomato paste, then add the taco seasoning, ground cumin, and black beans. Stir everything together until well combined and the tomato paste is fully incorporated. I like to taste the mixture at this point and adjust the salt and pepper to your preference—sometimes the taco seasoning varies in saltiness between brands, so it's better to check before baking.
• Transfer the entire beef and vegetable mixture from the skillet into your prepared baking dish, spreading it evenly. Sprinkle the 2.5 cups of shredded cheddar cheese evenly over the top, making sure to cover most of the surface—this helps it melt uniformly and creates a golden, bubbly top.
• Place the baking dish in the preheated 400°F oven and bake for 20-25 minutes, until the cheese is fully melted and the edges of the casserole are bubbling. The cooking time may vary slightly depending on your oven, so start checking around the 20-minute mark. I prefer to pull it out when the cheese has just turned golden at the edges—it gives the casserole better texture than pulling it out earlier.
• Remove the casserole from the oven and let it rest for 2-3 minutes before serving. Garnish with the fresh cilantro right before serving for a bright pop of color and flavor that cuts through the richness of the cheese.