14 cup unseasoned rice vinegar (more OK)
2 tablespoons grated fresh horseradish (prepared horseradish OK and more OK)
1 small garlic clove
12 cup extra-virgin olive oil
14 cup heavy cream
Puree 1/4 cup vinegar, 2 tablespoons horseradish, and garlic in a food processor. With motor running, gradually add oil in a slow, steady stream through the feed tube; process until well combined, then add heavy cream. Season dressing with salt, pepper, and more vinegar and horseradish, if desired. Store chilled in an airtight jar. Can be made 3 days ahead.