Loin of Mutton Roasted, on the Spit or in the Oven

Have a three pound loin of mutton; bone it entirely without detaching the minion fillet; remove the skin covering the fat and roll the flank over on itself as far as the minion fillet, then tie it firmly with five rounds of string, making a knot in each round, giving the loin the shape of a long square. Set it to roast either on the spit or in the oven; if for the former it will take from thirty to forty minutes, and a few more if for the latter. When the loin is cooked and of a fine color, untie, dress, and glaze it, strain the gravy, free it of its fat, and serve a part of it under the meat and the remainder separately.