Heat olive oil in a skillet over medium heat.
Add diced onions and bell peppers; sauté until softened.
Mix in the shredded chicken and taco seasoning.
Cook until heated through; season with salt and pepper.
Remove the chicken mixture from the skillet and set aside.
Place one tortilla in the skillet and sprinkle half the cheese on top.
Add half of the chicken mixture over the cheese.
Sprinkle the remaining cheese on top and cover with the second tortilla.
Cook until the bottom tortilla is golden brown, then flip carefully.
Cook until the second side is golden and cheese is melted.