Method

Pour 90 ml of the oil into a large saucepan and warm over a medium-high heat. Have a bowl of cold water ready by the hob. Add the onions to the oil and sauce until very dark golden brown; this should take about 25 minutes and produce a dark pasta. If it starts to catch on the base, add a little water. Set to one side.

Put the remaining 80 ml oil into a frying pan and warm over a medium heat. Add the curry leaves and let them crackle for 30 seconds. Add the garlic and ginger and fry for 4-5 minutes, until light golden brown.

Add the chilli powder, ground coriander, turmeric and salt and fry, stirring constantly, for 6-7 minutes. Add 1 tbsp of water if the mix gets a little claggy.

Add the tomatoes and cook for 12-15 minutes, or until they have disintegrated. Add 1-2 tbsp if the mixture dries up before the tomatoes are fully broken down.

Add the browned onions, sliced chilli, and coconut milk to the frying pan, stir well and simmer for 5 minutes, then add the tamarind chutney, lime juice and garam masala. Turn the heat down very low and add the crab meat, and warm through. Serve garnished with coriander and ginger, with lime wedges on the side.