When it comes to beef, tenderloin is one of the priciest cuts. Our recipe for Slow-Roasted Beef Tenderloin calls for a tenderloin roast that’s been trimmed of its silverskin and “chain,” or side muscle. If you want to purchase the roast completely trimmed and don’t mind paying top dollar for it, just ask your butcher to prepare the roast “side muscle off and skinned.” But if you’d rather save some money and you’re up for a little knife work, ask for a “peeled, side muscle-on” roast, and trim it yourself as shown at right. You’ll need to start with about 4-3/4 pounds to make up for the trim, but the price difference should still be worth it. Our untrimmed roast cost $6 less per pound, saving us about $15 in the end. Another bonus: You can save the chain for cooking another night (think stir-fry). It’s perfectly tasty beef, just not as tender as the rest of the tenderloin.