Heat olive oil in a skillet over medium heat. Add sliced chicken and cook until browned.

Add sliced bell pepper and onion to the skillet. Sprinkle with fajita seasoning and stir well.

Cook for an additional 5-7 minutes until vegetables are tender.

Serve the chicken and vegetable mixture in warm tortillas.

Add any desired toppings such as salsa, guacamole, or sour cream.