Real Turkish Shisk Kebab (Lamb)

Joe made this at Zachary's pre-graduation party
 
(Exceptionally tasty lamb!)
 
1 c. plain whole-milk yogurt
1/4 c. extra-virgin olive oil
2 cloves garlic, minced
2 tsp. Aleppo pepper flakes or 1 tsp. hot red pepper flakes
1 tsp. salt
1 tsp. freshly ground black pepper
1 1/2 pounds boneless loin or shoulder of lamb, cut into 1-inch cubes (include some fatty pieces)
8 fresh, ripe plum tomatoes or small round tomatoes
12 bull's horn peppers, stemmed (small version of red and yellow peppers)
2 tb. ground sumac, for serving (optional)
4 pita breads
Wooden skewers
 
1.  Combine the yogurt, oil, garlic, pepper flakes, salt, and pepper in a nonreactive bowl.  Add the lamb and toss to coat thoroughly.  Cover and let marinate, in the regrigerator, for 24 hours, stirring once or twice.
 
2.  Preheat the grill to high.
 
3. When ready to grill, remove the lamb from the marinade and thread onto the thin skewers, alternating lean and fatty pieces.  Thread the tomatoes onto a separate, flat skewer and the peppers onto another flat skewer.  Oil the grill grate, then arrange all the kebabs on the hot grate, and grill, turning  with tongs, until the skins on the vegetables are blistered and browned and the lamb is browned and done to taste, 8 to 12 minutes in all) for well-done.
 
4.  Using a pita to protect your hand, unskewer the lamb and vegetables onto serving plates, dividing the vegetables evenly.  Serve immediately.  (Serves 4)