Roast leg of lamb

Lamb and mutton, collectively sheep meat is one of the most common meats around the world, taken from the domestic sheep, Ovis aries, and generally divided into lamb, from sheep in their first year, hogget, from sheep in their second, and mutton, from older sheep. Generally, "hogget" and "sheep meat" are not used by consumers outside Norway, New Zealand, South Africa, Scotland, and Australia. Hogget has become more common in England, particularly in the North (Lancashire and Yorkshire) often in association with rare breed and organic farming. In South Asian and Caribbean cuisine, "mutton" often means goat meat. At various times and places, "mutton" or "goat mutton" has occasionally been used to mean goat meat.

Source: Wikipedia