Roasted Salmon with Celery and Bulgur Salad

Name: Roasted Salmon with Celery and Bulgur Salad
Ingredients: 1/2 cup walnuts; 1 (1 1/2-pound) piece skin-on salmon fillet; Kosher salt; 1/2 cup coarse whole grain bulgur (not quick-cooking); 2 bunches small white turnips (about 1 1/2 pounds total), trimmed; 4 tablespoons olive oil, divided; plus more for drizzling (optional); 1/4 cup plain Greek yogurt; 1 tablespoon white wine vinegar; 2 tablespoons fresh lemon juice, plus more for drizzling; 4 celery heart stalks, plus leaves for serving; 1/4 preserved lemon, flesh removed, rind finely chopped; 1/4 cup finely chopped golden raisins; 1/4 cup parsley leaves with tender stems