1. Toast English muffin on grill or in toaster and set aside.
2. Grill peppers and pineapple over medium heat/flame, carefully flipping until they begin to soften. Move peppers and pineapple to the top rack of the grill, or to a foil pan on the grill grate to continue cooking without direct heat.
3. Place chicken on hot grill and brush with barbecue sauce and a squeeze of lime juice. Cook about 6 minutes per side, adding more barbecue sauce and lime juice as it cooks.
4. Place chicken breast on English muffin base. Remove peppers from grill and cut into slices. Top chicken breast with grilled pineapple slice and 1 slice of each pepper color. Enjoy!