Buttermilk Fried Chicken with Pickled Peach-Fennel Salad

• 1 cup mayonnaise
• 2 tablespoons finely chopped celery
• 2 tablespoons finely chopped shallot
• 2 tablespoons nonpareil capers, chopped
• 2 tablespoons finely chopped fresh parsley
• 1 tablespoon ketchup
• 1 tablespoon Dijon mustard
• 1 teaspoon fresh lemon juice
• 1/2 teaspoon grated garlic
• 1/8 teaspoon kosher salt
• 2 cups whole buttermilk
• 2 pound bone-in, skin-on chicken thighs, bones removed
• 3 cups all-purpose flour (about 12 3/4 ounces)
• 1 tablespoon kosher salt, plus more
• 1 teaspoon black pepper
• 1 teaspoon garlic powder
• 1 teaspoon onion powder
• 1/4 teaspoon paprika
• 1/4 teaspoon cayenne pepper

Canola oil

• 1 fennel bulb, thinly shaved on a mandoline (about 1 3/4 cups), fronds reserved for garnish
• 1 tablespoon chopped yellow onion
• 1 cup water
• 1/2 cup rice vinegar
• 1 tablespoon granulated sugar
• 2 teaspoons kosher salt
• 3 (8-ounce) slightly unripe peaches, thinly sliced (about 4 cups)

1. Make the rémoulade Stir together all rémoulade ingredients in a bowl. Cover and chill until ready to serve, up to 3 days.
2. Make the fried chicken Place buttermilk in a large bowl; add chicken, and submerge in buttermilk. Cover; refrigerate at least 3 hours or up to 8 hours.
3. Stir together flour, salt, black pepper, garlic powder, onion powder, paprika, and cayenne in a shallow dish. Remove chicken from buttermilk; discard buttermilk. Dredge chicken in flour mixture, shaking off excess, and place in an even layer on a wire rack set inside a rimmed baking sheet. Let stand at room temperature 15 minutes.
4. Meanwhile, make the pickled peach-fennel salad Place fennel and onion in a medium-size heatproof bowl; set aside. Bring 1 cup water, vinegar, sugar, and salt to a boil in a small saucepan over high, whisking occasionally. Pour vinegar mixture over fennel mixture; let stand 10 minutes. Add peaches; toss gently to combine, and let stand 10 minutes. Drain, discarding vinegar mixture.
5. To fry chicken, pour oil to a depth of 2 inches in a large Dutch oven; heat to 350°F over medium-high. Working in batches, carefully add chicken thighs to hot oil; fry until golden brown and cooked through, 6 to 8 minutes, turning occasionally and maintaining an oil temperature of 325°F. Transfer to a wire rack set inside a rimmed baking sheet to drain; sprinkle evenly with salt to taste.
6. Spoon rémoulade onto 4 plates. Top with pickled peach-fennel salad and fried chicken. Garnish with fennel fronds.