Turkey offers little of the variety of chicken. Sizes range from 7 lb/3.2 kg to huge birds weighing 40 lb/18 kg, but all are tender enough to roast. Although it is hard to detect their age, most supermarket birds will be about nine months old. An older bird will be much too tough to roast and must be simmered slowly instead. Hen turkeys are rarely more than 16 lb/7.2 kg, and in Europe they are appreciated for their plump breast. In the United States the male is king: the bigger the turkey, the more it is admired, especially on the Thanksgiving table.