Mortadella Dumplings

Name: Mortadella Dumplings
Ingredients: Dumplings:; 8 ounces mortadella, cut into 1-inch chunks; 8 ounces ground pork; 1 tablespoon cornstarch; 1 tablespoon mirin; 1 tablespoon sesame oil, plus more to cook with; 1 tablespoon shaoxing wine or sake; 1 tablespoon soy sauce; Kosher salt and freshly ground black pepper; 1/2 cup finely diced cabbage; 1/4 cup finely diced Spanish onion; 1 tablespoon grated ginger; 3 cloves garlic, grated; 3 scallions, finely diced; 1 package dumpling or wonton wrappers, defrosted and covered with damp paper towel; Dipping Sauce:; 1/4 cup soy sauce; 1 tablespoon balsamic vinegar; 1 tablespoon chili flakes