Preheat the oven to 180°C/350°F/regulo 4.
If possible remove the wish bone from the neck end of the turkey for ease of carving. Also remove the fat from the vent end, season the cavity with salt and freshly-ground pepper and stuff with 2 or 3 sprigs of fresh marjoram.
Smear the breast of the turkey with 55 g/2 ozs of soft butter. Put the turkey breast-side down into a large saucepan and cook on a gentle heat for 6–8 minutes, or until the skin on the breast turns golden. Turn the other way up and smear with 2 tablespoons of chopped marjoram mixed with another 55 g/2 ozs of butter. Season with salt and freshly-ground pepper. Cover with greaseproof paper and a tight-fitting lid. Cook in a moderate oven for 2—2½ hours. Test to see if the turkey is cooked: the juices should be clear and there should be no trace of pink between the thigh and the breast.
Remove the turkey to a carving dish, allow to rest while the sauce is being made. De-grease the cooking juices, add the light cream, bring to the boil, taste, and reduce if necessary to strengthen the flavour. Add 2 more tablespoons of freshly-chopped marjoram. Add the juices from the carving dish to the sauce. Taste, correct seasoning.
Carve the turkey and nap with the sauce. Garnish with sprigs of fresh marjoram.