Roast beef cold cuts should be tender, flavorful, paper thin, and rosy pink throughout. While testing recipes for this issue, we discovered how to cook roast beef at home just the way we like it. First, because it should be served rare, buy top sirloin, a full-flavored cut that doesn't require long cooking to be tenderized. Get a five-pound piece and ask the butcher to tie it—this helps it to cook evenly and makes it easier to slice once it's done. Next, season the roast with salt and pepper, then sear it in a skillet on the stove. Finally, place it on a rack in a roasting pan in the oven and cook it at 200° for 3 hours 20 minutes, until a thermometer inserted in the center reads 130°. This is what sets this method apart: slow cooking at a very low temperature, the key to achieving a uniform pink color from center to edge. Once the roast beef is cooked, chill it in the refrigerator, then slice thin and pile it on your bread of choice.