1. Cut the lamb into large bite sized pieces, the meat should be marbled with fat which will melt during cooking, don’t remove. Set aside.
2. Let’s make the ‘tarka’. Take a medium-large lidded sauce pan, saute the onions, cassia bark, cardamom pods, cumin seeds, cloves, bay leaves and peppercorns in 2-3 tablespoons of vegetable oil on a moderate heat until the onions become translucent and soft.
3. Next add the garlic, ginger and chillies and cook out for a couple of minutes.
4. Now add the garam masala, turmeric and salt and toast off for 30 seconds. If the pan is too dry add a splash of water so the spices don’t stick to the pan and burn. Allow the spices to cook out for a minute.
5. Then pour in the passata. Increase the hob heat, and bring to a simmer. Allow to cook out for 5-10 minutes. When you can see the oil has separated on the surface of the masala it’s ready to taste. Check your seasoning here and adjust to taste.
6. Place in the lamb and mix together, coating all of the pieces. Do this on a high heat to seal the meat. Then reduce the heat to medium and stir in the yoghurt and a splash of water. Beware of adding too much water as the meat will shrink and also release water during cooking. (If you do add too much water you can correct at the end by simmering for an additional time, pan uncovered, and reduce the sauce).
7. Bring to the boil, then reduce the heat to medium. Simmer the lamb covered for 10-15 minutes.
8. Now add in the chopped carrots, a generous pinch of methi (dried fenugreek leaves) and mix. Re-cover with a lid, and simmer for a further 20 minutes, or until the lamb is soft and tender and the carrots cooked through. Don’t let the pan run dry, you may need a splash more water.
9. Finally scatter with a flurry of chopped coriander leaves.