Mexican Tortilla Casserole

Instructions:

1. Prepare the Oven: Preheat the oven to 400°F. Coat an 8×11 or 9×9 inch baking dish with cooking spray.
2. Cook the Onion Mixture: In a large skillet, warm the olive oil over medium-low heat. Add the onion, garlic, cumin, and chili powder. Stir and cook until the onions soften and the spices are aromatic (3-5 minutes).
3. Add Other Ingredients: Incorporate the tomatoes, reserved tomato juice, tomato paste, beans, corn, and spinach to the skillet. Cook for a couple more minutes until the spinach wilts and the corn has thawed. Season with salt and pepper.
4. Assemble the Casserole: Place two corn tortillas in the baking dish. Top with 1/4 of the bean mixture and spread it out evenly. Sprinkle 1/2 cup cheese over the top. Continue layering until all ingredients are used, ending with a layer of cheese.
5. Bake: Place the dish in the oven and bake for about 20 minutes, until the casserole is heated through.
6. Serve: Let the casserole cool for 5 minutes before cutting into portions. Serve with your choice of optional toppings.