Place the prawns in a bowl with the spices, chilli flakes, half the garlic, 1 tbsp lime juice and 1 tbsp olive oil. Mix until the prawns are well coated, then cover and leave to marinade at room temperature for 20 minutes.
Mix the remaining garlic and oil with the tomatoes, onion and coriander in a small bowl. Stir in 1 tbsp of lime juice and season to taste.
Heat a non-stick pan, add the prawns and cook for 3-4 minutes, turning occasionally, until prawns are piping hot and lightly charred. Warm the tortillas according to the packet instructions.
Serve the tortillas with the prawns, salsa and lettuce leaves and let everyone build their own. Garnish with the lime wedges and reserved coriander.
