Start this recipe by roasting the chicken. Place onto a baking tray and rub over the olive oil. Season all over with salt and pepper and cook in the oven at 200`c for 1 hour, or until the chicken is cooked through. Remove from the oven and allow to cool down before removing the chicken off the bone and shredding. Place the shredded chicken into a large bowl, add in the sticky Barbeque marinate and the sliced spring onions and mix together well. Meanwhile, make the coleslaw. Place the chopped green apple, carrots, red cabbage and red onion into a large bowl and mix in the lemon juice to stop from browning. Add the Tesco garlic Mayonnaise and mustard to the bowl, season well with salt and pepper and mix together. To serve, cut the burger buns in half and quickly toasted under a hot grill for a minute. Spoon the pulled chicken over the burger bun bases and top with the apple coleslaw. Place on the bun tops and serve.