Heat the olive oil in a large skillet over medium heat. Add the diced onion and cook for 3 to 4 minutes until it starts to soften.
Stir in the minced garlic and cook for 30 seconds until fragrant.
Add the black beans, frozen corn, enchilada sauce, cumin, chili powder, and salt. Stir everything together and let it simmer for 5 minutes.
Add the corn tortilla pieces and stir until they are coated in the sauce and starting to soften.
Sprinkle the shredded cheese evenly over the top. Cover the skillet and cook for 2 to 3 minutes until the cheese melts.
Remove from heat and serve with fresh cilantro and sliced avocado.