1 Place Lamb And Marinade Into A Plastic Bag. Squeeze Out As Much Of The Air As Possible From The Bag And Seal. Wrap Again With Another Plastic Bag To Ensure That The Marinating Lamb Doesn'T Leak. Marinate For Several Hours, Or Overnight, In The Refrigerator. Remove The Lamb, Still In Its Marinade Bag, From The Refrigerator At Least An Hour Before Putting In The Oven To Help Bring The Lamb Closer To Room Temperature Before Roasting. 2 Preheat Oven To 425