Easy Chicken Potstickers

Name: Easy Chicken Potstickers
Ingredients: 8 ounces finely shredded cabbage or coleslaw mix (about 3 packed cups); 1 teaspoon kosher salt; 1 large egg; 2 medium scallions, thinly sliced (about 1/4 cup); 2 tablespoons soy sauce; 2 cloves garlic, minced; 1/4 teaspoon freshly ground black pepper; 1 pound ground chicken; 1 (10- to 12-ounce) package round Asian dumpling wrappers (about 3 1/2 inches in diameter, sometimes labeled gyoza or potsticker wrappers); 1/2 cup vegetable oil, divided; 1/4 cup soy sauce; 3 tablespoons rice vinegar; 1 medium scallion, thinly sliced; 1 to 2 teaspoons chile-garlic sauce, such as sambal oelek (optional)