In a large mixing bowl, combine the ground pork, chopped kimchi, shredded onion, minced garlic, and grated ginger. Add soy sauce, rice wine, egg, and sesame oil. Sprinkle in salt and pepper to taste, then mix everything together thoroughly until well combined.

Cover the bowl with plastic wrap and let the filling sit for at least 20 minutes at room temperature, or ideally, refrigerate it overnight.

While the filling marinates, set up your workspace by laying out dumpling wrappers on a clean surface. Have a small bowl of water at hand to seal the edges of the wrappers.

Take one dumpling wrapper and wet the edges with water. Place about a tablespoon of the filling in the center. Fold the wrapper in half and pinch the edges tightly to seal.

For pan-frying, heat a tablespoon of oil in a pan over medium heat. Cook dumplings until golden brown, about 3 minutes. Add water and cover, steaming for 7-8 minutes. Crisp for an additional 2 minutes.

For boiling, drop dumplings into boiling water and cook until they float, approximately 5-7 minutes, then drain.

Plate your freshly cooked Kimchi Dumplings, garnishing with sesame seeds and finely chopped green onions. Serve warm with your choice of dipping sauce.