- 2 onions, 1½ roughly chopped, ½ thinly sliced
- 100g/3½oz rogan josh spice paste (or follow pack guidance for serving 4 people)
- 600g/1lb 5oz lamb neck fillet or shoulder, excess fat trimmed and diced into 3–4cm/1¼–1½in chunks
- 1½ tsp cumin seeds
- 1 cinnamon stick
- 2 fresh or dried bay leaves
- 400g tin plum tomatoes
- 1 pepper, any colour, cut into big chunks (optional)
- 100g/3½oz full-fat Greek-style or plain yoghurt
- salt and freshly ground black pepper
- freshly cooked rice (or options described in the introduction), to serve
Turn the slow cooker to the High setting to heat up. Put the roughly chopped onions and curry paste in a food processor with 100ml/3½fl oz water and whizz until smooth. Scrape into the slow cooker, then add the thinly sliced onion, lamb chunks, cumin seeds, cinnamon and bay leaves.
Use kitchen scissors to snip the plum tomatoes into small pieces inside the tin, then tip into the slow cooker. Give everything a good stir, season with salt and pepper and cover with the lid. Cook for 4 hours on High or 8–9 hours on Low until the lamb is tender, but not dry. If using the pepper, add for the last hour of cooking.
Stir in the yoghurt and leave for 10 minutes before serving. Taste and season again if needed and serve with rice or preferred serving options.