1.Combine ground cumin and cardamom.
2.Combine lamb with paste and half the yoghurt in a large bowl. Combine remaining yoghurt in a small bowl with cucumber, onion and half of the combined spices.
3.Place rice and saffron in a large saucepan of boiling water; cook until rice is tender. Drain; place rice in a large bowl.
4.Toast remaining spices in a heated dry small frying pan until fragrant; stir into saffron rice, cover to keep warm.
5.Cook undrained lamb, in batches, on a heated lightly oiled grill plate (or grill or barbecue) until browned and cooked as desired.
6.Serve lamb on saffron rice, accompany with cucumber raita.
You can marinate the lamb a day ahead; store, covered, in the refrigerator. The cucumber raita can be made several hours ahead; store, covered, in the refrigerator.Note