1/4 cup champagne vinegar
1/4 cup lemon juice
2 tablespoons freshly grated horseradish
2 tablespoons minced shallots
1/2 teaspoon sugar
Salt and freshly ground black pepper, to taste
Oysters on the half shell
In a small bowl, whisk together champagne vinegar, lemon juice, horseradish, shallots, and sugar.
Season to taste with salt and pepper. Serve as a topping for oysters.