4 tablespoons unsalted butter, softened
2 large eggs, room temperature
1 cup whole milk, room temperature
1 teaspoon kosher salt
1/2 teaspoon sugar
1 cup all-purpose flour
1/4 cup prepared horseradish
1/4 cup sour cream
2 tablespoons chopped fresh chives
Kosher salt and freshly ground black pepper
Kosher salt and freshly ground black pepper
8 ounces sliced roast beef
Finishing salt, to top