- 2 tablespoons unsalted butter
- 1/2 teaspoon kosher salt
- 1/4 teaspoon cayenne pepper
- 1 large egg white
- 1/2 cup (packed) light brown sugar
- 2 cups walnut halves
- 2 cups cashews
- 1 1/4-inch-thick slice white bread, torn
- 1 garlic clove, finely grated
- 1/4 cup fresh lemon juice
- 1/2 teaspoon ground coriander
- 1/2 cup olive oil
- Kosher salt
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil, plus more
- 1/2 (3 1/2–4-pound) chicken (backbone removed)
- Kosher salt
- 1 celery stalk, thinly sliced, plus 1/4 cup celery leaves
- 1 tablespoon mixed unsalted, roasted seeds (such as pumpkin, sunflower, and/or hemp)
- 2 teaspoons fresh lemon juice
- Preheat oven to 300°F. Melt butter in a small skillet over medium, remove from heat, and mix in salt and cayenne. Whisk egg white in a medium bowl until soft peaks form; stir in brown sugar. Add seasoned butter and walnuts and fold to coat nuts.
- Spread nuts out on a parchment–lined rimmed baking sheet; bake, tossing every 10 minutes or so, until mixture is dry and nuts are toasted, 25–30 minutes. Let cool.
- Increase oven temperature to 350°F. Toast cashews on a rimmed baking sheet, tossing once, until golden brown, 8–10 minutes. Let cool.
- Pulse cashews, bread, garlic, lemon juice, coriander, and 3/4 cup water in a food processor to combine. With motor running, stream in oil; process just to incorporate. Pulse, adding a splash or so of water if too thick, until a coarse purée forms; season with salt.
- Increase oven temperature to 475°F. Heat butter and 1 Tbsp. oil in a large skillet over medium-high. Once butter is foaming, place chicken in pan, skin side up. Tilt pan and spoon butter mixture over chicken until the entire surface is coated. Sprinkle with a generous pinch of salt and transfer to oven. Roast chicken, rotating pan halfway through, until skin is golden brown and an instant-read thermometer inserted into the thickest part of a thigh registers 165°F, 25–30 minutes. Transfer chicken to a cutting board and let rest 5 minutes.
- Meanwhile, toss celery, celery leaves, mixed seeds, lemon juice, and 1/2 cup spicy walnuts in a medium bowl. Drizzle with oil, season with salt, and toss again.
- Spoon tarator onto a platter and top with celery salad and chicken.
- Spicy Walnuts can be made 5 days ahead. Store airtight at room temperature. Cashew Tarator can be made 1 day ahead. Cover and chill. Bring to room temperature before using.