In a medium pan, heat 1 tablespoon olive oil over medium-high heat. Add bell pepper and red onions and sprinkle with salt. Sauté for 6-8 minutes, until onion is translucent.
Add garlic and jalapeño and sauté 1 minute more, until aromatic.
Add the ½ cup enchilada sauce, frozen corn, black beans, chili powder, cumin and lime juice. Cook over medium until the corn is defrosted, about 4-5 minutes.
Spread 1 cup of enchilada sauce into a 9x13 inch or similarly sized casserole dish.
To make the enchiladas: Add a heaping ½ cup of the black bean filling to a tortilla and roll up tightly. Line up the enchiladas in the glass dish with the fold down.
Spread remaining ½ cup enchilada sauce, or additional black bean filling, on top of the enchiladas.
Sprinkle with 1 and ½ cups of cheese. Bake, uncovered, on the middle rack for 15-18 minutes at 350F, or until the cheese is melted.
Remove from the oven let rest for 5 minutes. Serve topped with diced avocado, cilantro, salsa and additional lime wedges.
Enchilada sauce: Choose mild, medium or hot red enchilada sauce based on your spice preference.
Freezing instructions: You can cover the entire casserole dish tightly with foil and freeze it or freeze individual portions in freezer-safe containers. Freeze for up to 3 months. Let thaw overnight in the fridge before reheating.
Storage and reheating: Keep refrigerated for up to 4-5 days for best quality. Reheat individual portions in the microwave in about 2 minutes.
To reheat in the oven: Heat the oven to 350 degrees. Place the entire casserole dish, uncovered, in the oven and bake for 15-20 minutes, or until the enchiladas are heated through.