Cut the chicken breast into bite-sized pieces.
Add olive oil to a pan and cook the chicken breast.
Once the chicken is cooked, add barbecue sauce and stir-fry.
Slice lettuce, tomato, cucumber, and onion.
Slice the bread (flatbread or wheat bread) in half.
Place the vegetables on the bread and then add the barbecue chicken.
Add your desired sauce to complete the sandwich.