Heat 1 tablespoon of oil in a large skillet over medium-high heat.
Add sliced bell peppers and onion. Season with salt and cook for about 5 minutes until softened.
Transfer vegetables to a plate.
Add another tablespoon of oil to the skillet.
Add chicken strips and season with chili powder, cumin, oregano, and salt.
Cook for about 8 minutes, stirring occasionally, until golden and fully cooked.
Transfer chicken to a plate and carefully wipe out the skillet.
Add 1 tablespoon of oil to the skillet and place one tortilla in the pan.
Sprinkle cheese over half of the tortilla.
Add a portion of chicken, peppers, onion, avocado slices, and scallions.
Fold the tortilla in half and cook for about 3 minutes per side until golden and crispy.
Repeat with remaining tortillas and filling ingredients.
Slice into wedges and serve warm with sour cream.