Serve this at room temperature. Two hours before serving, remove from the refrigerator.
- 1 Yukon gold potato (3 ounces), peeled and sliced
- 2 bunches fresh flat-leaf parsley, roughly chopped (2 1/2 cups chopped)
- 1/2 small red onion, chopped (about 3 ounces)
- 6 cornichons, finely chopped
- 2 cloves garlic, finely chopped
- 2 slices (each 1 inch wide) green bell pepper, finely chopped
- 4 tablespoons capers
- 1 teaspoon crushed red-pepper flakes
- 1 cup extra-virgin olive oil
- 3 tablespoons red-wine vinegar
- Salt and freshly ground black pepper
Place the potato in a small saucepan; cover with cold water. Place over high heat; bring to boil. Reduce heat to medium, and simmer until tender, 8 to 10 minutes. Drain, and mash very well with a fork; set aside.
Combine remaining ingredients in the bowl of a food processor, and pulse briefly until mixture is coarsely pureed. Transfer mixture to a medium bowl; whisk in reserved potato until well combined. Season with salt and pepper, cover, and transfer to the refrigerator.