Best Reuben Sandwich Recipe? My Classic Deli Secret!

Ingredients

• 1/2 cup (120 ml) mayonnaise
• 2 tablespoons (30 ml) ketchup
• 1 tablespoon (15 ml) sweet pickle relish
• 1 teaspoon (5 ml) prepared horseradish
• 1/4 teaspoon (1 ml) Worcestershire sauce
• Pinch of smoked paprika
• Salt and freshly ground black pepper to taste
• 4 slices rye bread
• 4 tablespoons (60 ml) unsalted butter, softened
• 8 ounces (225g) thinly sliced corned beef
• 1 cup (115g) sauerkraut, well-drained
• 4 slices Swiss cheese