Whisk together the sauce mix ingredients in a bowl. Add prawns, covering them completely, cover with cling film then pop in the fridge to marinade for at least 30 minutes.
Blend all dipping sauce ingredients together until smooth. Season to taste then pour into a small bowl.
Fire up the grill on the barbecue on medium heat.Remove prawns from the fridge and then push onto skewers. Push mango strips onto skewers.
Drizzle barbecue with oil then lay prawn skewers on and grill both sides until cooked and slightly charred, about 3-5 minutes each side. Baste with extra oil as you grill.
Sprinkle cooked skewers with toasted sesame seeds and serve with lime wedges and dipping sauce. Yum!