Step 1

Put the cashew nuts in a bowl and pour boiling water over them.

Step 2

Heat 1 tbsp oil in a frying pan, then add the mustard and cumin seeds and cook for a few minutes until they start to pop.

Step 3

Add the onion, green chillies and a good pinch of salt and fry until softened.

Step 4

Add the ginger, garlic, chilli flakes and the rest of the spices and cook for a couple of minutes.

Step 5

Stir in the lamb steaks and fry, stirring for a few minutes until they’re browned all over.

Step 6

Drain the cashews and whizz in a blender with the coconut milk.

Step 7

Pour into the pan with the lamb and add the chicken stock. Cover and simmer for 1 hour, or until the lamb is tender.

Step 8

Add the spinach and cook uncovered for another 10 minutes (turn up the heat if you want a thicker sauce).

Step 9

Serve with rice and naan bread.