Heat 375ml water in a large saucepan. Add all the curry base ingredients apart from the tomato and simmer covered for 45 minutes until the onions become very soft. Add the tomatoes and cook for a further 15 minutes.

Remove from heat and blend to a smooth consistency in a blender, or with a hand blender. Set this curry base aside until needed.

Begin by braising your meat. In a food processor, blitz the garlic and ginger, adding a little water if needed to loosen and turn into a paste.

In a karahi, or heavy bottomed pan, heat the oil over a medium heat. Add the lamb pieces and fry for 3-4minutes, until browned. Next add the garlic and ginger paste from the blend and cook for a further two minutes.

Next add the fenugreek, black pepper, chilli flakes, cumin powder, coriander powder and green chilli, along with the water, and simmer for approximately 1 ½ hours, or until the meat is tender. Keep checking the water and top up if needed, by the end of cooking there should only be a small amount of water left.

Remove lamb and set aside, and clean out pan. Return to a medium heat and add the reserved 2tbsp oil. Add diced onion and cook for 5-6minutes, or until lightly browned. Add onion seeds and garam masala and cook for a further two minutes.

Next, add diced tomatoes and cook for 2-3minutes until the tomatoes have broken down a little.

Finally, add the curry base and the lamb back to the pot and allow to simmer for 10-15minutes, allowing the sauce to thicken and coat the lamb.

Garnish with chopped coriander and serve with rice, naan and mango chutney.