Heat a small pan over medium heat. Once hot, put the coriander and cumin seeds into the heated pan. Toast the spices until they become aromatic. This will only take a few minutes. Remove from heat, allow to cool, then grind to a fine powder.
Put the lamb mince in a large bowl. Add the ground coriander and cumin seeds, onion, ginger, garam masala, chilli powder, salt, coriander stalks, mint and yoghurt. Mix well. Cover and refrigerate at least overnight.
to make the koftas
Pre-heat oven to 175 °C
Take the mixture and divide it into 12 equal portions. Wet your hand and form each into a ball. Now, with dry hands, dust with chickpea flour, and gently shape again.
Use kitchen scales to weigh the mixture, then divide by the number of koftas you want to make. Portion your mixture by using the scales to get consistently sized koftas.
Line a baking tray with greaseproof paper. Place the koftas on the tray in a single layer and bake for 30 minutes, turning every 5 minutes to make sure that the koftas retain their ball shape. Set aside in a warm place once cooked.
to make the gravy
Heat a small pan over medium heat. Once hot, put the coriander seeds into the heated pan. Toast them until they become aromatic. This will only take a few minutes. Remove from heat and allow to cool, then grind them to a fine powder and set aside
Heat the mustard oil in a pan big enough to just take the cooked koftas in a single layer. A 24cm (9½ inch) pan should suffice.
When the mustard oil stops smoking and appears translucent, remove it from the heat and allow it to cool a little. Add the mustard seeds, fennel seeds, curry leaves and dried chillies. Return to heat, and cook until mustard seeds begin to splutter.
Add the onions, sprinkle with the salt and cook for ten minutes, stirring frequently until the onions start to brown at the edges.
Add the turmeric, tomatoes, garlic and the water and mix well. Simmer until the tomatoes soften and the oil starts to separate from the mixture. This will take about ten minutes.
Add the Kashmiri chilli powder and ground coriander seeds. Stir well and cook for another two minutes.
Add the tamarind water and cook for a further two minutes.
Using a vegetable masher or a stick blender, puree the gravy, getting as many large pieces of tomato reduced. Bring to a boil, then reduce heat to a very low simmer.
Add the juices from the cooked koftas to the mixture, then mix well. Gently add the koftas in a single layer, ensuring they are coated with the sauce.
Cover the pan and poach the koftas in the gravy for 20 minutes, gently turning them every five minutes.
to serve
Remove the koftas from the gravy, and place them into a warm serving dish.
Stir the gravy, and slowly add the coconut milk. Season with salt, if needed, and bring to a simmer. Do not overheat the sauce as the coconut milk will separate.
Pour the gravy over the koftas, then sprinkle with coriander leaves and serve.
notes
Use the leanest minced lamb you can obtain. Some fat will keep the koftas moist, but too much fat content will spoil the dish. A good butcher will make this mince for you from a suitable piece of lamb leg.Be careful with the size of the koftas. You should have 12 koftas, each about billiard ball size, each weighing about 85g (3 oz).If making cocktail-sized koftas, divide lamb mixture into 18 portions, each weighing about 60g (2 oz)