Preheat the oven to 200C/400F/Gas 6.
To make the prawns, place the honey, soy sauce and olive oil into a bowl and whisk together.
Add the prawns and leave to marinate for two minutes.
Heat a griddle pan until smoking. Add the prawns and char-grill for two minutes on each side, or until cooked through. Retain the marinade.
To make the mango salsa, place the mango, chilli flakes and spring onion into a bowl and mix together well.
To make the prawn oil, heat the oil in a medium frying pan. Add the prawn shells and the tomato purée and fry for four minutes. Carefully strain the oil into a bowl and discard the shells.
To serve, spoon the mango salsa into the centre of a plate, place the cooked prawns on top and drizzle the soy sauce and honey marinade and prawn oil around the plate.