In a large pan, heat the olive oil on medium high heat and fry the chicken breasts until cooked through ( 5-10 minutes per side depending on size). You may pound the chicken prior for faster cooking. Set aside.
Wash and dry lettuce. Chop tomato, onion, and jalapeño (removing seeds if desired, as seeds add heat).
On a dish or cutting board, cut chicken vertically to shred, throw back into the pan and sauté in the buffalo sauce mixture, about 5 minutes.
Place chicken in lettuce shells and top with remaining ingredients. Serve immediately and enjoy!