No matter what it costs, a holiday roast should taste rich. So we challenged ourselves to transform a thrifty, low-cost cut into an impressive meal. The answer was eye round, a roast often deemed too lean to be tender. The cut is taken from the hind leg of a steer, so there’s little marbling, the usual key to keeping meat moist. To roast this tough cut and get succulent, perfectly cooked results, we marinated the meat in ingredients that would do the work for us. We started with a sticky, sweet puree of prunes. That may sound unusual, but prunes are high in hygroscopic sorbitol and fructose, which—along with salt and soy sauce—amplify the way the meat absorbs flavor. Thinly sliced and served with a fresh horseradish sauce, the eye round was as toothsome as beef tenderloin, without the expense.