Fry 2 large, sliced onions in 4 tablespoons of oil until browning.
Skoosh up a two inch piece of ginger and 3 cloves of garlic and add to the onions. Stir this into the onions with a teaspoon each of chilli powder, turmeric, ground cumin and salt. Continue stirring and cook for 2 minutes more.
Add 500g lean diced lamb (I usually buy a leg or shoulder joint and cut it up myself so that there is no visible fat) and stir well. Add half a tin of chopped tomatoes and stir. Then add 400ml water and stir. Put the lid on and cook slowly for 50 minutes.
Add 200g chopped spinach and cook – lid on – for a further 10 minutes. Then take the lid off and turn up the heat to reduce the liquid for the last ten minutes.
Garnish with sliced chillis, ginger or coriander.