Heat up a large saucepan on medium-high heat with one tablespoon olive oil. Add diced onion and cook until becomes translucent (2-5 minutes). Then add the red bell peppers and zucchini for an additional 3-5 minutes. Add the ground cumin, garlic powder and chili powder. Combine until well mixed and flavors are immersed.
Turn heat to low. Add the can of black beans and Kernel Corn to the saucepan until well combined. Pour in 2 cups of the Red enchilada sauce. Save one cup of the sauce from the can for the topping of the casserole.
Spray the bottom of slow cooker well with nonstick spray.
Add one layer of tortilla to bottom (3 tortillas). Some tortillas will need to be broken in half to fit the slow cooker.
Add 1/2 of vegetable mixture on top of corn tortillas to cover. Sprinkle with 1/3 of the cheese.
Repeat another layer. (3 corn tortillas, 1/2 of the vegetable sauce and 1/3 of the cheese)
Top with 3 more corn tortillas, then one cup of the enchilada sauce that you saved. Sprinkle withe the remaining cheese.
There will also be leftover enchilada sauce as the recipe doesn't use the entire can, however you can save in a container for a few days as well! I typically use less than 3 cups so the large can works for this recipe.
Place lid on top and cook on high for 2 hrs. Top with cilantro, diced tomato, and sliced avocado.
Notes
Place any remaining vegetarian casserole in an airtight container and store in the fridge for up to 4 days.
Don't have Enchilada sauce? You can use salsa and taco seasoning; however, the consistency and taste will differ.