
This vegetarian Mexican tortilla casserole has become a staple in my household for those busy weeknights when we crave something comforting yet nutritious. The layers of corn tortillas, seasoned beans, and melted cheese create a satisfying meal that pleases everyone at the table.
I first made this casserole when hosting friends with different dietary restrictions and was thrilled to discover a dish that satisfied both vegetarians and those avoiding gluten. Now it appears on our dinner table at least twice a month, especially when I need a reliable crowd pleaser.
Ingredients
- Extra virgin olive oil: provides the perfect base for sautéing vegetables with a mild flavor that lets other ingredients shine
- Red onion: adds a pleasant sweetness and beautiful color that regular onions cannot match
- Fresh garlic cloves: deliver essential aromatic flavor look for firm bulbs without any sprouting
- Red bell pepper: contributes sweetness vitamin C and a pop of color choose ones that feel heavy for their size
- Mushrooms: create a meaty texture and umami depth slice them uniformly for even cooking
- Taco seasoning: infuses authentic Mexican flavor throughout the dish use homemade if you have time
- Tomato purée: forms the saucy base that holds everything together opt for no salt added if watching sodium
- Kidney or black beans: provide plant based protein and fiber rinse well to remove excess sodium
- Sweet corn: adds bursts of sweetness and textural contrast frozen works perfectly when fresh is unavailable
- Fresh cilantro: brings brightness and authentic Mexican flavor choose bunches with vibrant green leaves
- Corn tortillas: form the essential layers while adding authentic flavor look for non GMO varieties
- Cheddar cheese: creates that irresistible gooey topping freshly grated melts more smoothly than pre shredded
Step-by-Step Instructions
- Prepare the Baking Dish:
- Preheat your oven to 400°F or 200°C which ensures the casserole cooks evenly and allows the cheese to melt perfectly without burning. Take a 9x13 inch baking dish and grease it thoroughly to prevent sticking. This size provides the ideal depth for proper layering of all ingredients.
- Sauté the Aromatics and Vegetables:
- Heat the olive oil in a large skillet over medium heat until it shimmers but does not smoke. Add the chopped red onion garlic diced bell pepper and sliced mushrooms. Cook for approximately 3 minutes stirring occasionally until the onions become translucent and the mushrooms begin to release their moisture. Avoid overcooking as the vegetables will continue to soften in the oven.
- Create the Filling Mixture:
- Add the tablespoon of taco seasoning to the vegetable mixture and stir for about 30 seconds to bloom the spices. This awakens their essential oils and intensifies the flavor. Pour in the tomato purée followed by the drained beans corn chopped cilantro salt and pepper. Stir everything together ensuring all ingredients are evenly coated in the sauce. Let this mixture cook for 2 minutes to allow the flavors to meld. Taste and adjust seasoning if needed before removing from heat.
- Assemble the Casserole:
- Cut each corn tortilla into 4 equal pieces. Place 8 tortilla pieces on the bottom of your prepared baking dish arranging them to cover the surface as much as possible. Spoon one third of your bean mixture over the tortillas spreading it into an even layer. Sprinkle half a cup of cheddar cheese evenly over this layer. Repeat this layering process two more times finishing with a generous cup of cheese on top ensuring complete coverage for that perfect golden crust.
- Bake to Perfection:
- Place the assembled casserole in your preheated oven and bake for approximately 15 minutes until the cheese has melted completely and begun to bubble around the edges. The top should become slightly golden but not browned. Once done leave the casserole in the open oven for 5 minutes this resting period allows it to set slightly making it easier to serve in clean portions.
- Finish and Serve:
- Garnish the finished casserole with additional freshly chopped cilantro which adds color freshness and enhances the Mexican flavor profile. Serve hot allowing each person to dig through the delicious layers of tortilla beans and melted cheese.

The red bell pepper is actually my secret hero in this recipe. I discovered its importance when I ran out once and made the casserole without it. The dish lacked that subtle sweetness and vibrant color that balances the earthiness of the beans. My daughter immediately noticed something was missing proving how essential this ingredient is to the overall flavor profile.

Frequently Asked Questions
- → Can I make this casserole ahead of time?
Yes, you can assemble it ahead and refrigerate for up to 24 hours before baking.
- → What can I substitute for cheddar cheese?
You can use Monterey Jack, mozzarella, or a plant-based cheese for a dairy-free option.
- → Is this casserole freezer-friendly?
Absolutely! Assemble the casserole, cover it tightly, and freeze for up to 3 months. Thaw before baking.
- → Can I make this dish spicier?
Yes, add chopped jalapeños or a pinch of chili powder to the veggie mix for extra heat.
- → What can I serve with this casserole?
Pair it with a fresh green salad, guacamole, or Mexican-style rice for a complete meal.