An easy version of this favourite dish from Sat Bains.
Heat the oil in a large, heavy-bottomed saucepan on a low heat and add the onions, garlic and ginger. Cook with the lid off, on the lowest setting, for at least one hour, stirring regularly. If the mixture starts to catch on the bottom at any point, add a splash of water.
Add the chopped chillies, turmeric and chopped tomatoes and cook uncovered for a further 20 minutes, stirring regularly.
Add the minced lamb, stirring to break it up, and salt to the sauce. Cook, uncovered, for another 25 minutes. Add the frozen peas and cook for 10 more minutes. Taste for seasoning and add more salt, if needed.
Finish with plenty of fresh coriander.