Sauté onion until fragrant.
Add green chiles, sauté a couple minutes.
Add chicken, enchilada sauce, chicken taco seasoning, lime juice, and cilantro. Let simmer for a few minutes, then set aside.
Steam tortillas in damp paper towels in microwave for 30 seconds (make sure to work quickly before they cool down).
Spray sheet pan with avocado spray. Place tortillas on sheet pan, and spray tortillas. Flip them over and add cheese and chicken filling to the top half, and gently fold in half to not break the tortilla.
Bake tacos at 400 degrees F for 15-18 minutes.
While tacos bake, make sauce to your liking.
Top with lettuce and other toppings of your preference!