Heat the oil in a large skillet over medium-high heat. Carefully add the zucchini, corn, and peppers. Stir everything together and season with salt and pepper. Let the veggies hang out for 2-3 minutes to pick up color before pushing to one side of the pan.

Add the ground beef to the other side and brown one side before breaking apart and mixing together with the veggies. Continue cooking until no pink remains in the beef. (If the pan is going to be crowded, you can cook the beef first and remove from the pan to cook the veggies for a full 5-6 minutes on their own.)

Turn off the heat and add the enchilada sauce, stirring everything together.

Add the chopped corn tortillas, give everything one final stir, and top with shredded cheese. Cover the skillet to melt or pop under the broiler for a few minutes.

Garnish with diced avocado, cilantro, lime wedges, and cotija cheese.