Grilled Skewered Lamb (Boti Kabab)

This recipe is not original and I have not tried it. I have lost the source

2 lb. boneless leg of lamb, cut into 1-1/2-inch cubes
1 t ground cumin
1/2 t ground turmeric
2 t salt
1/4 c. yogurt
1/4 c. finely chopped onions
2 T finely chopped cilantro
2 T finely chopped ginger
1 t minced garlic
1/2 teaspoon garam masala

Place the lamb pieces in a deep bowl and sprinkle it with the cumin, turmeric, and salt, turning them to coat evenly. Add the yogurt, onions, cilantro, ginger, and garlic and toss until well blended. Marinate the lamb overnight in the refrigerator.

Prepare barbecue grill. Remove the lamb from the marinade and string pieces on long metal skewers. Grill approximately 3" from hot, white coals, turning occasionally, for approximately 10 to 20 minutes. Lamb should be cooked to your taste.

To serve, sprinkle with garam masala