Wash the cashewnuts, and then soak them in a bowl of water for a couple of hours.
Chop onions and the chilli.
Remove the cashew nuts from the water, drain them and place them in a saucepan together with the chilli, 1 tsp of curry powder, the turmeric, coconut milk, chilli powder, salt, fenugreek and curry leaves.
Boil and simmer for 5 mins.
Heat oil in a frying pan and toss in onion for a couple of minutes.
Add the cashewnut mixture and cook for a further 3-4 mins.