Combine with butter, rosemary, salt and pepper. For those of us who are used to cooking up a 20+ pounder, dealing with a small turkey (we’re talking 10 pounds or less) is a bit of a mystery. Roast for the first stage for about 10 minutes per pound (so, for a 20 pound turkey, about 3 1/2 hours.) Roast turkey recipes It's a once-a-year affair, cooking a turkey, and not the easiest Christmas dinner either! Using a vegetable peeler, shave off thick slices of orange peel and slice them very thin.