makes one platter serving 6–8 people as an appetizer or brunch side dish with enough dressing for leftovers (3 cups); adapted from Food & Wine magazine, December 2010
Macerate the minced shallots in the vinegar for 10 minutes—this mellows out the shallot.
Mix together the buttermilk, mayonnaise, and sour cream in a bowl or 4-cup glass measure. Crumble in the blue cheese, add the macerated shallots and vinegar, and mix and mash using a whisk or spoon. Season with salt and black pepper. Refrigerate until ready to use. (This dressing will keep for a week, refrigerated.)
Assemble on a platter: radicchio and endive leaves, apple slices, grape clusters, and toasted walnuts. Set bowl of blue cheese dressing in center or nearby. Enjoy!