1. Scrub the sweet potatoes clean, lightly poke the skin with a fork and wrap them in tin foil. Bake on the grill at high indirect heat for about 30-35 minutes, depending on their size.
2. Add BBQ sauce to the chicken breast and season with salt and pepper. Barbecue for 6-7 minutes on each side, then let rest for 5 minutes. Shred the chicken breasts using two forks.
3. Slice open the sweet potatoes and top with shredded chicken. Add sour cream and grated Castello Extra Mature Cheddar.
4. If you want the cheese to melt, just put the loaded sweet potato on the grill with the lid on for 2-3 minutes. Garnish with spring onions and BBQ or hot sauce.