The flesh of grass or yearling lamb (often incorrectly and confusingly called “baby lamb”) is tender but its structure is that of a mature animal. It is, when of good quality, well furnished with white, dry, and rather crumbly fat and the flesh is a clear rose-tan. Older mutton has a reddish-brown flesh and the flavor is stronger, but all the methods of treating it are the same. Milk lamb, a traditional Easter dish, has a pale grayish-pink flesh, is best roasted to assume a glorious, crackly golden surface; it should always be cooked well done. It is as different from grass lamb as is veal from beef and, for those of delicate digestion, should probably be avoided. All of the following recipes are for grass or yearling lamb.
American habits of cutting lamb are a windfall to the stewmaker and a disaster for the roaster: The shanks (easily the best stew pieces for flavor, moistness, and leanness) are chopped off both the legs and the shoulders, a “leg of lamb” being often composed only of the upper half of the leg plus a section of the saddle, creating a bizarre form and a complication of bone structure at the heart of the roast that renders both decent presentation and elegant carving out of the question; the animals are usually split and often cut up in advance, thus destroying the double saddle, one of the handsomest and, when kept pink, finest of roasts . . . If you have a good butcher and order in advance, everything can be arranged. Lamb should be aged for perfect flavor and tenderness; American butchers are often more serious on this score than the French.
The spareribs are the most economical and probably the commonest stew cut. They are, for some tastes, unpleasantly fat and their structure does not permit its being removed; unless you are certain of your company, you’d best stick to the shanks. Stock will not improve a lamb stew, but a certain amount of tomato will flatter its distinctive flavor and lend warmth to the sauce. A navarin, the classic French lamb stew, is prepared like the stew recipe-type, moistened only with water and about