Gratinéed Oysters with Sauerkraut
2 cups coarse sea salt
16 large oysters, such as wellfleet, bluepoint,
5 tbsp. butter
1 medium yellow onion, finely chopped
3⁄4 cup dry white wine
1⁄2 lb. sauerkraut, rinsed and drained
Kosher salt and freshly ground white pepper,
3⁄4 cup heavy cream
1 tbsp. dry vermouth
1 egg yolk
Pinch of cayenne
1. Spread sea salt on a large baking sheet. Open oysters over a cheesecloth-lined sieve over a bowl to collect oysters' liquor. Remove oysters and chill. Discard flat top shells. Wash bottom shells and place on sheet; set aside.
2. Heat 3 tbsp. of the butter in a pot over medium heat. Add half the onions and cook until softened, 5–7 minutes. Add 1⁄2 cup of the wine, sauerkraut, and salt and pepper; boil. Reduce heat to medium; simmer, partially covered, 8–10 minutes. Drain the sauerkraut mixture and set aside.
3. Heat remaining butter in a pot over medium heat. Add remaining onions; cook until softened, 5–7 minutes. Add oyster liquor, remaining wine, 1⁄2 cup cream, and vermouth and bring to a boil. Lower heat to medium-low; reduce by half, about 20 minutes. Remove from heat; whisk in egg yolk and remaining cream. Add cayenne and season with salt and pepper. Set sauce aside.
4. Heat broiler with rack 4" from element. Divide sauerkraut between shells; top each with an oyster. Spoon some sauce over each and broil until light golden brown, about 5 minutes.
SERVES 6 – 8