Northumbrian duck is not a duck, as in a bird, at all.
It is actually a recipe for lamb, cooked and shaped to look like a duck decoy on a platter.
To make it, you use a special cut of a shoulder of lamb. The shoulder is first cut with an extra 2 inches (5 cm) of bone on the trotter side, which is then split to form a beak. The rest is boned, except for the knuckle bone, which is used to shape the neck and head. The whole cut will weigh about 5 to 6 pounds (2 to 2.5 kg.) It costs more of course for this special cut, because it is extra work for the butcher.
At home in the kitchen, you push a wooden skewer in the front part to keep the it standing up, then turn the joint over, stuff the cavity, then sew it up underneath and turn it back right side up.
You then make scalloped incisions which will resemble feathers, sprinkle with flour, and roast with the head part covered with foil so that it won’t burn.
You serve on something that will resemble a pond, such as a bed of peas.
Grigson, Jane. Northumbrian Duck. Manchester: The Observer. 12 August 2001.
Lanchester, John. The Debt to Pleasure. Toronto, Canada: McClelland & Stewart, 1997. Page 80.