Slash fat edges of lamb steaks in several places to keep steaks flat while broiling. To marinate, place steaks in plastic bag; set in deep bowl. Combine oil, onion, vinegar, wine, garlic, salt, rosemary, thyme and pepper. Pour herb mixture over steaks; close bag Marinate in refrigerator for 6 hours, turning occasionally.
Place steaks on an unheated rack in broiler pan, reserving 3 tablespoons of marinade. Broil 3 inches from heat for 5-7 minutes. Turn and continue to broil for 5-7 minutes more to desired doneness. Combine mint jelly and marinade; serve warm with lamb steaks. Makes 4 servings.