How to Make It
Place potatoes in a large saucepan, and cover with water; bring to a boil. Reduce heat; simmer 12 minutes or until tender. Drain and set aside.
Combine cumin and next 8 ingredients (cumin through garlic); add lamb, tossing to coat. Cover and refrigerate 20 minutes.
Thread 4 lamb pieces, 2 potato halves, and 2 onion pieces alternately onto each of 12 (12-inch) skewers. Place kebabs on a grill rack coated with cooking spray; grill 4 minutes on each side or until lamb reaches desired degree of doneness.