3. Heat oil in a heavy medium pot over medium heat. Add garlic, onions, and bell peppers and cook for 5 minutes. Add pepper flakes and cook for 2 minutes. Add lamb pieces, remaining 1/2 cup wine, and reserved sauce, decrease heat to medium-low, and simmer stew for 45 minutes. Add pimientos, cover pot, and gently simmer stew until lamb is very tender, 2-3 hours more.