1 shallot, minced 2 tablespoons cider vinegar Salt ½ pound jewel yams, peeled and cut into ½-inch dice ¼ pound fingerling potatoes, peeled and cut into ½-inch dice ¼ pound Peruvian blue potatoes, peeled and cut into ½-inch dice ½ cup mayonnaise (homemade preferred) 1 teaspoon Dijon mustard 1 tablespoon capers, soaked in water for 15 minutes and drained 1 tablespoon chopped parsley Pepper to taste 1 Gala apple, peeled, cored, and cut into ½-inch dice 1 long, slender fennel bulb, halved, cored, and thinly sliced across the grain In a small bowl, combine the minced shallot with the cider vinegar and a pinch of salt; mix well and set aside. Place three small pots on the stove. Fill each pot with water to cover potatoes by 2 inches and season with 1 teaspoon of salt. Put each type of potato (yams, fingerling, and blue) in a separate pot. Turn on the stove and bring each pot to a simmer over medium heat. Cook the potatoes until each is just tender, about 6 to 8 minutes. Drain the potatoes and spread them on a sheet tray to cool slightly. In a large bowl, combine the mayonnaise, shallot-vinegar mixture, mustard, capers, parsley, and pepper to taste. Gently fold in the potatoes, apples, and fennel. Serve at room temperature.