Cut the chicken breast into bite-sized pieces.
Julienne the onion and bell pepper.
Heat olive oil in a pan and sauté the chicken breast.
Add onion and bell pepper and stir-fry together.
Lightly toast the tortilla in a pan and lay it flat.
Place the grilled chicken and vegetables on the tortilla.
Add lettuce, cheese, and sauce.
Roll up the tortilla to make a wrap.