Ingredients

• 6 medium shallots
• 4 tablespoons (1/2 stick) chilled unsalted butter
• 1 1/4 cups Madeira
• 1 tablespoon drained green peppercorns in brine, coarsely chopped
• 2 1 1/4-pound racks of lamb, trimmed

Instructions

1. Finely chop 2 medium shallots. Melt 1 tablespoon unsalted butter in heavy small saucepan over medium heat. Add chopped shallots and sauté until tender, about 3 minutes. Add Madeira and green peppercorns. Boil uncovered until mixture is reduced to cup, about 12 minutes. Remove sauce from heat.
2. Arrange trimmed racks of lamb on rimmed baking sheet. Cut remaining 4 medium shallots in half and push through garlic press. Coat lamb with pressed shallots. Sprinkle with salt and pepper. (Can be prepared 8 hours ahead. Cover sauce and lamb separately and refrigerate.)
3. Preheat oven to 400°F. Roast lamb 25 minutes. Increase heat to 500°F and continue to roast until lamb browns and meat thermometer inserted into center of lamb registers 130°F, about 5 minutes longer. Let stand 5 minutes.
4. Bring peppercorn sauce to simmer. Whisk in remaining 3 tablespoons butter. Season to taste with salt and pepper. Cut lamb between ribs into chops. Arrange lamb chops on plates. Spoon peppercorn sauce around lamb and serve.