300 g tuna fillet, cut into bite-sized pieces
1 tsp chilli powder
1 sprig curry leaves, plus extra to serve
1 lime, juiced
2 Tbs oil
1 onion, peeled and quartered
3 garlic cloves, peeled and finely chopped
2 leeks, washed and chopped
3 banana chillies, chopped
2 long red chillies, finely chopped plus extra to serve
2 green chillies, finely chopped, plus extra to serve
3 Tbs tomato sauce
3 Tbs vinegar
Place the tuna in a bowl with salt, chilli powder, curry leaves and lime juice. Stir to coat the tuna and set aside to marinate for 10 minutes.
To make the sweet and sour sauce, combine the tomato sauce and vinegar and set aside until ready to use.
Heat the oil in a wok over high heat. Once it reaches smoking point, add the onion, garlic and leek. Cook for a few minutes, until the mixture is fragrant and the onion is translucent. Add the chillies and fry for a few minutes, stirring occasionally.
Add the tuna and toss to coat in the spice mixture. Stir in the sweet and sour sauce and cover. Leave to cook for a few minutes, or until the tuna is just cooked.
Season with salt and pepper and serve sprinkled with curry leaves and the reserved chilli.