2 onions, 1½ roughly chopped, ½ thinly sliced
1 pepper, any colour, cut into big chunks (optional)
100g/3½oz rogan josh spice paste (or follow pack guidance for serving 4 people)
freshly cooked rice (or options described in the introduction), to serve
400g tin plum tomatoes
2 fresh or dried bay leaves
salt and freshly ground black pepper
1 cinnamon stick
1½ tsp cumin seeds
100g/3½oz full-fat Greek-style or plain yoghurt
600g/1lb 5oz lamb neck fillet or shoulder, excess fat trimmed and diced into 3–4cm/1¼–1½in chunks