- 1/2 cup chopped walnuts
- 1 medium shallot, halved lengthwise, divided
- 2 tablespoons whole grain mustard
- 1 teaspoon sugar
- 1/2 cup sherry vinegar or red wine vinegar, divided
- 1/3 cup olive oil
- Kosher salt, freshly ground pepper
- 6 dried Turkish figs, very coarsely chopped
- 1 fennel bulb, core removed, very thinly sliced
- 6–8 celery stalks, very thinly sliced
- 4 ounces blue cheese, crumbled
- Preheat oven to 350°F. Toast walnuts on a rimmed baking sheet, tossing once, until golden brown, 5���8 minutes; let cool.
- Finely chop 1 shallot half, then thinly slice the other half crosswise; set sliced shallot aside. Combine chopped shallot, mustard, sugar, and 1/4 cup vinegar in a resealable jar. Add oil and season with salt and pepper. Cover and shake to emulsify; set vinaigrette aside.
- Toss figs, reserved sliced shallot, and remaining 1/4 cup vinegar in a small bowl; let sit until figs and shallots are softened, at least 30 minutes.
- Just before serving, toss fennel, celery, blue cheese, and toasted walnuts in a large bowl. Drain figs and shallot and add to bowl. Drizzle with vinaigrette and toss to coat; season with salt and pepper.
- Vinaigrette can be made 1 day ahead; cover and chill. Figs and shallot can be soaked 4 hours ahead; store covered at room temperature. Fennel and celery can be sliced 4 hours ahead; place in a large bowl. Cover with a damp paper towel and chill.