To butterfly the chicken, place chicken breast-side down on a clean work surface. Using chicken shears or a sharp knife, cut on either side of the backbone and discard backbone. Trim and discard rib bones. Turn chicken over and using the palms of your hands, firmly press the breastbone to butterfly open the chicken. Score the chicken flesh in the thickest parts

To make the marinade, combine piri piri sauce, oil, garlic and lemon juice in shallow ceramic dish. Add chicken and liberally brush on both sides with marinade. Cover and chill for 15 minutes (or longer if time permits)

Preheat a greased barbecue over medium-high heat. Insert 2 long metal skewers lengthways into the thickest parts of the chicken. Place chicken onto the barbecue grill and cook for 15 minutes, brushing occasionally with remaining marinade. Turn and cook, brushing with any remaining marinade for a further 15 minutes. Reduce heat to medium-low and cook for 20-25 minutes or until just cooked through. Serve with coleslaw, barbecued lemon wedges, extra piri piri sauce and crusty bread rolls

Combine coleslaw mixture and salad seeds in a large bowl. Mix mayonnaise with lemon juice and mustard in a small bowl. Season with salt and pepper. Drizzle mayonnaise mixture over coleslaw and gently toss to combine. Cover and chill until ready to serve