1¼ cups prepared horseradish
½ cup vinegar, preferably champagne
⅓ cup simple syrup
1¼ cups water
Pour 1 cup of sugar and 1 cup of water in a saucepan and bring to a boil. Stir until sugar is dissolved completely. Cool.
Combine all ingredients in a blender and blend thoroughly. Strain onto a wide and shallow container and freeze. When thoroughly frozen, scrape with a fork to create a shaved ice. Serve on oysters immediately.