This sparkling, vodka-laced granita has a peppery kick that sets off the briny sweetness of a good West Coast oyster. Prep Time: 15 minutes, plus 3 hours of freezing time. Notes: You can make granita up to 3 days ahead. Re-rake with fork before serving. Also, if you're serving the oysters on a buffet, serve on crushed ice with the granita in a bowl alongside, also on ice.