Lazy Skillet Dumplings with Spicy Dipping Sauce

Ingredients

• 3 tablespoons cornstarch
• 2 tablespoons soy sauce
• 3 tablespoons water
• 2 teaspoons sesame oil
• 1½ teaspoons grated fresh ginger, from a 1-in (2.5-cm) knob
• 3 scallions, light and dark green parts, finely chopped (plus more for serving, if desired)
• 2 cloves garlic, minced
• 1 teaspoon sugar
• Heaping ¼ teaspoon salt
• 1/4 teaspoon white pepper
• 1 lb ground pork
• 22 to 24 Hong Kong-style dumpling wrappers (or wonton wrappers; see note)
• About ¾ cup water
• Vegetable oil, for cooking
• 3 tablespoons soy sauce
• 1½ tablespoons rice vinegar
• 1 to 1½ teaspoons chili crunch or chili oil, to taste (see note)
• 1 tablespoon sugar