Roast Beef and Horseradish Sandwich

Roast beef and horseradish is one of the oldest pairings in the American and British culinary traditions, rooted in the same instinct that puts horseradish sauce alongside a Sunday prime rib: the fiery, sinus-clearing bite of horseradish root cuts through the fat and richness of beef in a way few other condiments can. This sandwich takes that steakhouse pairing and turns it into a five-minute, no-cook lunch by whisking prepared horseradish straight into mayonnaise, which mellows the heat just enough to spread generously without overwhelming the beef. Piling on peppery arugula and thinly sliced red onion nods to the modern deli sandwich shops that popularized dressing up cold cuts with fresh, slightly bitter greens instead of plain lettuce — arugula's pepperiness actually echoes the horseradish, so the whole sandwich reads as a single cohesive flavor rather than a pile of separate toppings. Served on a crusty roll instead of soft sandwich bread, it holds together under a generous pound of beef and doesn't turn soggy, making it equally at home in a packed lunch, a picnic basket, or a quick dinner when nobody wants to turn on the stove. It's the kind of sandwich that rewards good ingredients: quality deli roast beef and a roll with real chew are what separate this from an ordinary cold-cut sandwich.