A mignonette sauce is typically made from vinegar, shallots, and black pepper, and spooned onto oysters and clams on the half shell. Mignonettes add a bit of sharpness to the briny, creamy oysters. Jenny Appleton, who visits the Vineyard each summer from California, adapted the signature oyster topping from California’s Hog Island Oyster Company on Tomales Bay. It has a wonderful flavor from the rice vinegar—more mellow than most red wine vinegars. Seasoned rice vinegar contains a bit of sugar and salt and balances with the unseasoned vinegar here in this adaptation. Jenny sometimes makes it spicy, adding a small amount of chopped jalapeño.