Beat a 3-4 lb. boned, rolled (string-tied) lamb shoulder roast on all sides with heavy rolling pin. Scald with 1/4 cup boiling vinegar. Slice 4-5 buds garlic and 1 small onion into slivers, make scattered slits all over the roast with the tip of a sharp knife, and insert the garlic and onion slivers into them.

Rub roast all over with salt, pepper, and marjoram, and let stand covered at room temperature for 1 hour. Roast meat uncovered on rack in roaster in 350° oven 2-2'/2 hours

At start of roasting, add several Tablespoons boiling water to roaster and baste occasionally with pan drippings. Roast is done when a fork goes in easily and a cloudy, pale-pink juice drips out of stab mark. Meat should still be faintly pink on the inside. 

For well-done roast, keep in oven a while longer. For a crispier skin, roast in 400° oven the first 15 minutes, then turn meat over and continue roasting at 350° . 

Remove roast from oven and allow to set 15 minutes before slicing. Serve with mashed potatoes, sprinkled with some of the pan drippings, braised beets, or Brussels sprouts and a zesty grated-vegetable salad containing horseradish.