You will need a charcoal or gas grill, 12 to 15 small bamboo or metal skewers, and a spice grinder or mortar and pestle.
Preheat grill. If using bamboo skewers, soak in water for 30 minutes. Remove excess fat from the meat. Cut lamb into small chunks, 1/2-inch across or less. Thread them onto skewers, without packing them too tightly together.
Grind or pound together the cumin, cayenne, and black pepper to a blended powder. Using your hands, rub spice mixture onto the skewered meat. Grill lamb for 5 to 8 minutes over hot coals. Halfway through the cooking, sprinkle the kebabs with a little salt.