Peel and finely dice the onion. Add the oil to a frying pan and sauté the onion until it is starting to turn golden. Remove from the pan and add to the slow cooker.
1 large onion, 1 tsp vegetable oil
Cook the diced lamb in the pan, frying gently until the edges are browning. Fry in batches to make sure the meat cooks in contact with the pan.
600 g lamb
Add the spices, grated ginger and chopped garlic. Return all the meat to the pan. Stir to coat the lamb. and continue until the spices are starting to toast, and release their fragrance.
1 tbs fresh ginger, 2 cloves garlic, 2 tbs curry powder, 1 tsp garam masala, 1 tsp chilli flake, 1 tsp paprika, 2 tsp cumin
Add the lamb to the slow cooker together with the tomatoes, tomato puree, coconut milk, stock/broth, butter, cinnamon stick and cracked cardamom pods.
1 cinnamon stick, 1 can tomatoes, 2 tbs tomato paste, 1 can coconut milk, 1 lamb, chicken or vegetable stock cube / stock pot, 30 g butter, 6 cardamon pods
Stir well and put the lid on. Cook for half an hour on high, until the curry starts to simmer. You can then continue to cook for a further 4+ hours on high, or turn down to low for 6+ hours.
Towards the end of cooking, remove the cinnamon stick and cardamom pods. These will have floated to the top and can be lifted out with a spoon.
If you prefer a thicker gravy, you can now thicken the curry. You can do this by leaving the lid ajar for the last 30-40 minutes of cooking, to allow the sauce to reduce, or use cornflour. Put 2 heaped teaspoons of cornflour/cornstarch into a small bowl. Then scoop out a few spoons of the curry sauce and stir into the cornflour to make a thin paste. Pour into the curry and stir through.Do not be tempted to add the cornflour directly to the curry. It will clump and you will never get the lumps out. 2 tsp cornflour/cornstarch