Preheat oven to 400 degrees and pierce sweet potatoes several times with a fork.
Line a baking sheet with foil then place a cooling rack on top, then place the sweet potatoes on top of the cooling rack.
Roast for 45 minutes to 1 hour and 15 minutes, depending on how big the sweet potatoes are, or until a knife can be easily inserted into the center.
When sweet potatoes have 20 minutes left, season chicken breasts with salt and pepper then sauté in a large skillet until cooked through. Once cool enough to handle, shred chicken with two forks then mix with enough BBQ sauce to coat.
Slice sweet potatoes in half lengthwise, then use tongs to press the ends towards each other to help open them up.
Fill the openings with shredded BBQ chicken then top with a quarter of the shredded cheese and place back onto the cooling rack. Broil until the cheese has melted and serve with desired toppings.