Step 1

Boil the potatoes for 5 minutes in salted water, then drain. Whizz the onion, garlic, ginger, chilli and 2 tbsp of water to a purée

Step 2

Heat 1 tbsp oil in a pan. Cook the whole seeds for a minute until they pop. Add the rest of the spices and cook for a minute, then add the purée and cook for 5 minutes. Add the tomatoes, sugar and tamarind, and simmer for 10 minutes. Add the potatoes and a splash of water, put on a lid and cook until the potatoes are completely tender but still holding their shape. Stir in the coriander and serve with rice or naan bread.