Gourmet Deli Roast Beef Sandwich

A deli roast beef sandwich is a wonderful thing: a succulent tower of paper-thin slivers of rare red meat, perched on sliced seeded rye, slathered with mustard. Properly made, it threatens to be too tall to eat, but anyone with a firm grip will make the tender meat comply, squishing down just enough for that first juicy bite. The perfect lunch to get you through the winter.