Prep 30 mins
Cook 2 hrs
Adapted from "The Beekman 1802 Heirloom Vegetable Cookbook". Tangy buttermilk and rich nuts tame the peppery flavor of raw red radishes, which give this refreshing soup a purple-pink hue (although you can use radishes of other colors). Although the soup makes a lovely first course for a casual dinner, you could also set out smaller servings in shot glasses for an elegant outdoor-party appetizer. Make Ahead: The soup can be refrigerated for up to 1 week or frozen for up to 3 months. The garnishes can be refrigerated for up to 3 days; the sliced radishes should be stored in water to prevent discoloration. This can be made vegetarian by omitting the egg garnish, and vegan by substituting the buttermilk for non-dairy milk with vinegar (1 cup non-dairy milk to 1 tbsp. vinegar or lemon juice, let stand 5 minutes to curdle). "Cook" time is chilling time.
- 8 ounces red radishes, scrubbed, trimmed and thinly sliced
- 2 cups buttermilk, preferably low-fat
- 1⁄4 cup walnuts (may substitute pecans)
- 1 tablespoon red wine vinegar
- 1⁄2 teaspoon coarse salt, plus more for the potato cooking water
- 1⁄2 teaspoon sugar
- 8 ounces yukon gold potatoes
- 2 large eggs
- 1⁄4 cup red onion, finely diced
- 1 persian cucumber, sliced thin
- Place all but 1/4 cup of the radish slices in a blender with the buttermilk, walnuts, vinegar, the 1/2 teaspoon of salt and the sugar; puree until smooth. Refrigerate until chilled.
- While the soup is chilling, cover the potatoes with salted water in a small saucepan. Bring to a boil over high heat, then reduce the heat to medium or medium-low so the water is barely bubbling; cook until the potatoes are fork-tender but not falling apart, about 30 minutes. Run under cold water, peel and cut into 1/2-inch chunks.
- Place the eggs in a separate saucepan. Cover with cool water and bring to a boil over high heat, then remove from the heat, cover and let stand for 12 minutes. Crack the eggs, transfer them to a bowl of ice water and let them stand for 10 minutes (to make peeling easier). Drain the eggs, then peel them and slice into thin rounds.
- To serve, divide the soup among chilled bowls. Garnish with the potato, egg, red onion, cucumber and the reserved radish slices.