In a medium bowl mix together the lime juice, oil, garlic, Worcestershire sauce, brown sugar, jalapeño cilantro, salt and pepper. Reserve ⅓ cup of the marinade and set aside. Place chicken in the marinade, cover and let sit in the refrigerator 15-30 minutes.
Brush the peppers and onion slices with oil and season with salt and pepper.
Place vegetables and marinated chicken on grill, turning the chicken 45 degrees after about 3 minutes to create grill marks.
Continue to cook peppers and onions, flipping them until they are charred and the onions are translucent.
Flip chicken breast and continue cooking until they reach 160 degrees or are no longer pink inside. Transfer to a platter and allow chicken to rest, so juices redistribute.
Separate the onions into rings and slice the peppers and chicken into strips.
Drizzle remaining marinade over the chicken and vegetables and toss to coat.
Serve the chicken and vegetables with the flour tortillas and your choice of toppings.