Ingredients
4 tablespoons chili powder
3 tablespoons chopped fresh cilantro
1 tablespoon dried oregano
1 tablespoon ground cumin
1 1/2 teaspoons garlic powder
8 1-inch-thick lamb loin chops (about 2 3/4 to 3 pounds total)
1 tablespoon olive oil
1/4 cup chopped shallots
1 tablespoon chopped garlic
2 cups dry red wine
2 cups beef stock or canned beef broth
4 tablespoons (1/2 stick) chilled butter, cut into 1/2-inch pieces

Directions
Combine 2 tablespoons chili powder, cilantro, oregano, cumin and garlic powder in small bowl. Coat lamb chops with spice mixture. Place lamb chops in glass baking dish. Cover and refrigerate 8 hours or overnight.

Heat 1 tablespoon oil in medium saucepan over medium-high heat. Add shallots and garlic and saute 2 minutes. Add red wine, beef stock and remaining 2 tablespoons chili powder. Boil until sauce is reduced to 3/4 cup, about 30 minutes. Remove sauce from heat. Add butter 1 piece at a time, whisking until melted after each addition.

Prepare barbecue (medium-high heat) or preheat broiler. Grill or broil lamb chops to desired doneness, about 6 minutes per side for medium-rare.  Place 2 lamb chops on each of 4 plates. Spoon sauce over lamb and serve. Serves 4.

   
Source:  Bon Appétit