Cook your bacon. I bake mine on a foil-lined, rimmed baking sheet in the oven at 350° for about 15 minutes or until it's as crispy as I like.
As the bacon cooks, place chicken breasts in a baking dish or ziploc bag and cover with 3/4 cup barbecue sauce. Place remaining 1/2 cup barbecue sauce in a small bowl. Let chicken marinate in the refrigerator for 15 minutes. Turn all burners of your grill on to high, cover, and heat grill until hot, about 15 minutes.
Turn burners down to medium-high. Clean and oil cooking grate. Place chicken on the grill and cook until browned on first side, 2 to 2 1/2 minutes. Flip chicken, brush with some of the reserved barbecue sauce, and cook until browned on the second side, 2 to 2 1/2 minutes. Flip chicken, brush with barbecue sauce, and cook for 2 minutes. Repeat flipping and brushing two more times, cooking for 2 minutes on each side. Flip chicken again and brush with any remaining sauce. Cook until chicken registers 160 degrees, 1 to 3 minutes. Turn off the grill and top each chicken breast with two slices of bacon. Sprinkle with shredded cheese. Close the grill lid and let the chicken rest for 1 minute to melt the cheese. transfer chicken to a clean plate and let rest for 5 minutes. Serve with diced tomatoes, sliced green onions.
You can easily adjust this recipe to serve more or less. Plan for two pieces of bacon, about 1/4 cup barbecue sauce and about 1 tablespoon of shredded cheese per chicken breast.
For food safety, discard the barbecue sauce that the chicken marinates in (do not use it for basting).
We often use a grill mat when grilling with marinades because clean up...