Add olive oil, lime juice, brown sugar, garlic, chili powder, cumin, salt and pepper to a bowl for the marinade. Whisk together until well combined.
Mix chicken into marinade, cover and refrigerate for at least 1 hour or up to 8 hours.
Prepare a grill fire to 350° using hickory, oak or pecan chunks for smoke flavor.
Use a cast iron skillet, grill pan or griddle over hot grill. Mix marinated chicken and sliced vegetables and add to the grill pan.
Cook with the grill closed, stirring every 5 minutes.
Continue to cook until chicken reaches 165° using a digital meat thermometer and vegetables should be softened.
Remove from the grill.
Slice a small section out of the top of each roll to make room for the filling. Place rolls on a sheet pan.
Add 2-3 slices of pepper-jack to the rolls and fill with chicken fajita mixture.
Return to the grill or place under oven broiler for about 5 minutes or until rolls are toasted and cheese is bubbly.
Remove from grill or oven and serve immediately.