Preheat the oven to 400°F (200°C).
Heat the olive oil in a large oven-safe skillet over high heat.
Toss the sliced chicken with 1–2 tablespoons fajita seasoning, salt, and pepper, then add to the hot skillet and sear until browned on all sides, about 4–6 minutes.
Add the sliced onion and bell peppers to the skillet, season with a little more salt and pepper, and cook until softened and fragrant, about 5 minutes.
Remove the skillet from heat and stir in the enchilada sauce or salsa verde, coating the chicken and vegetables evenly.
In a mixing bowl, combine the corn, cream cheese, Greek yogurt, chili powder, chopped chives, and a pinch of salt; stir in half of the shredded Mexican cheese until combined.
Spoon a portion of the corn mixture down the center of each warmed tortilla, tuck and roll, then place each filled tortilla seam-side down on top of the chicken in the skillet.
Sprinkle the remaining shredded Mexican cheese evenly over the top of the tortillas.
Bake in the preheated oven for 15–20 minutes, until the cheese is melted and bubbly.
Remove from the oven, drizzle with mayonnaise, sprinkle with Tajin or cayenne, and top with diced avocado, cilantro, cotija cheese, and lime wedges to serve.