GNOCCHI
Rock salt
3/4 pound Yukon Gold potatoes
1 cup sour cream
1 large egg, lightly beaten
1 cup all-purpose flour
2 teaspoons kosher salt
1/4 teaspoon freshly grated nutmeg
SAUCE
6 tablespoons unsalted butter, softened
6 small garlic cloves, minced
1/3 cup finely chopped parsley
Salt and freshly ground black pepper
3/4 cup dry white wine
One 12-ounce can small Burgundy snails, drained and rinsed
2 tablespoons extra-virgin olive oil
1 pound oyster mushrooms, stems trimmed and large caps halved
1 teaspoon sherry vinegar
1/4 cup freshly grated Parmigiano-Reggiano cheese
2 cups small watercress sprigs