Cover chicken breast with plastic wrap and pound it to even thickness, about 1 inch.
Mix Worcestershire sauce, olive oil and half of the lime juice. Place chicken in a shallow container or large zip top baggie and pour over the top. Let marinate for 30 minutes, turning chicken over halfway through.
Meanwhile, slice bell pepper and onion and place in a cast iron skillet coated with olive oil. Set aside for later. Wrap tortillas in foil and set aside.
Remove chicken to a plate and sprinkle one side with half of the chipotle, garlic powder, salt and pepper. Turn over and sprinkle with the remaining seasoning. Squeeze remaining lime juice over the top.
Heat a grill to medium high heat. Place skillet with veggies onto the grill and cook, stirring until cooked but still firm. Place on the top rack to keep warm while you grill the chicken.
Spray grill with oil. Place chicken breast on the grill and cook about 10-15 minutes, turning once, until the center reaches 145°F.
While chicken is cooking, warm tortillas on the top rack of the grill.
Remove chicken to a cutting board and slice thinly. Add sliced chicken to the skillet with veggies and serve with tortillas, guacamole, cheese, sour cream, and salsa.