1. Marinade the lamb in salt, red chilli powder, garam masala, malt vinegar, ginger and garlic pastes, papaya paste, kachri and cumin seeds for 4 hours or overnight.
2. Skewer pieces 1 inch apart and roast on a slow fire in a tandoor or charcoal grill for 15 minutes or till half done.
3. Stand at room temperature for 20 minutes. Baste with oil.
4. Roast or grill on slow fire for another 20 minutes, till velvety brown.
5. Serve with onion rings, fresh green salad and lemon wedges.