Cauliflower florets are a sly substitute for half of the baby potatoes in this creamy salad. The white-on-white combo gets zingy lift from briny capers, mustard and freshly grated horseradish.

Ingredients

  • 3 pounds cauliflower, cut into 1-inch florets
  • 1/4 cup grapeseed oil
  • Kosher salt
  • 1 1/4 pounds fingerling potatoes, halved lengthwise and sliced crosswise 1/4 inch thick
  • 2 tablespoons Champagne vinegar
  • 1 1/4 pounds baby red potatoes, halved and sliced 1/4 inch thick
  • 1 cup mayonnaise
  • 2 small shallots, minced
  • 2 tablespoons Dijon mustard
  • 1/4 cup brined capers—drained, rinsed and finely chopped
  • 1/4 cup finely chopped parsley, plus more for garnish
  • Finely grated fresh horseradish, for serving

Directions

  1. Preheat the oven to 400°. On a large rimmed baking sheet, toss the cauliflower with the oil and season with salt. Roast for 25 to 30 minutes, stirring once, until just tender and lightly browned; let cool.

  2. Meanwhile, in a large saucepan of salted boiling water, cook the fingerlings just until tender, about 8 minutes. Using a slotted spoon, spread the fingerlings on a large baking sheet and sprinkle with 1 tablespoon of the vinegar. Repeat with the baby red potatoes and remaining 1 tablespoon of vinegar; let cool.

  3. In a large bowl, whisk the mayonnaise, shallots, mustard, capers and the 1/4 cup of parsley. Add the cauliflower and potatoes and toss. Season with salt and garnish with parsley. Serve with horseradish.