Prep: Preheat oven to 350 degrees F while you are preparing the roast. How to Roast a Turkey Breast 1. Stuff with Garlic. Make holes in the roast: In a medium roasting pan or Dutch oven, place turkey roast and make 10-15 inserts with a paring knife. Chop rosemary and cut garlic into thin slivers. Stuff with garlic: Stick garlic slice into each hole until you run out of garlic. Allow about six hours for the turkey to cook on low setting. Turn the wings back to hold the neck skin in place. Place turkey breast side up on a flat rack in a shallow roasting pan 2 to 2½ inches deep. Cooking a Butterball turkey breast in a Crock-Pot is a convenient way to make a moist, tasty dish.