Lamb Rogan Josh recipe | Morrisons

Whisk together the yogurt, saffron and ginger-garlic paste in a bowl. Season with salt. Pour the marinade over the lamb cubes, cover and refrigerate for 2 hours. Before cooking, remove the lamb from the fridge and allow it to come to room temperature for about 30 minutes.

Using a pestle and mortar, pound the cumin seeds, cardamom pods, cinnamon stick, cloves and star anise together to release the oils. Coarsely crush them—do not grind to a fine powder.

Heat the olive oil in a large heavy-based frying pan over a medium-high heat. Add the pounded whole spices and stir constantly for about 1 minute until they crackle and become fragrant.

Immediately add the sliced onions to the pan before the spices burn. Stir well and cook over a medium heat for 8–10 minutes, stirring frequently, until the onions are deep golden brown. This caramelisation is crucial for the rich colour and flavour of the sauce.

Add the marinated lamb (including all the yogurt marinade) to the pan. Stir well and cook over a medium-high heat for about 5 minutes, scraping the bottom of the pan frequently to incorporate the browned bits and prevent sticking. The lamb should begin to brown but does not need to be fully cooked through at this stage.

Add all the powdered spices (nutmeg, black pepper, red chilli powder, ground coriander, garam masala and ground turmeric) and cook for 2 minutes, stirring constantly, to toast the spices slightly.

Stir in the tomato purée and mix well until all the meat is evenly coated.

Transfer the entire contents of the pan to your slow cooker. Stir well. Cover and cook on the Low setting for 8 hours or on the High setting for 5 hours. The lamb should be very tender and the sauce should be rich and aromatic.

Just before serving, taste and adjust the seasoning with salt if needed. Garnish with the fresh chopped coriander leaves and julienned ginger. Serve hot with basmati rice, naan bread or roti.