Ginger Scallion Lo Mein

Name: Lo Mein with Ginger-Scallion Sauce and Pickled Vegetables
Ingredients: 1/2 cup plus 2 teaspoons rice vinegar; 2 tablespoons sugar; Kosher salt; 2 Persian cucumbers, thinly sliced; 4 radishes, thinly sliced; 1 small turnip, peeled and cut into thin wedges; 1 small red jalapeño pepper, thinly sliced (remove seeds for less heat); 3 bunches scallions, thinly sliced; 1/2 cup minced peeled fresh ginger (from about three 2-inch pieces); 2 teaspoons low-sodium soy sauce; 1/2 cup vegetable oil; 1 pound fresh lo mein noodles, cut into thirds with kitchen shears; 1/4 cup oyster sauce