Place prawns in a bowl with garlic, ginger and sesame oil. Mix well and leave to marinate from 6 to 24 hours.
To make salsa, mix onion with citrus juice, zest and salt and stand at least an hour, then mix in mango and tomatoes and stand another hour. Finally mix in olive oil and figs.
Wipe excess marinade from prawns. Heat up the barbecue, grill or heavy-bottomed frying pan and