Add ground pork into a large bowl. Add 4 tablespoons water. Mix well with a spatula until water is fully incorporated.

Add Shaoxing wine, light soy sauce, dark soy sauce, salt, sugar, grated ginger, cornstarch, and scallion. Mix well.

Add chestnuts and eggs. Mix a few times.

Add panko. Mix well. Add sesame oil, mix until it forms a soft paste.

Heat peanut oil in a nonstick skillet over medium heat until warm.

Use bare hands to scoop about 1/3 cup of the paste and shape it into a meatball (*see footnote 1). The meatball should be a bit runny, barely able to hold its shape (so the finished meatballs will be tender and juicy). If the meatballs cannot hold their shape, add a bit more panko and mix again. If the meatballs are still a bit tough, blend in more water and mix well, 1 tablespoon at a time, until the paste turns soft.

Carefully place 3 to 4 meatballs in the skillet and make sure to leave enough space to flip them. When the bottom side is just set, carefully roll the ball with a spatula to cook the other sides. Continue to do this until all sides are set and browned (*see footnote 2). Transfer to a plate. Continue to brown the rest of the meatballs.

Add water to a steamer and place the plate of meatballs on the steaming rack. (*see footnote 3)

Heat the steamer over medium high heat, covered, until the water begins to boil. Turn to medium heat. Cook covered until the meatballs are cooked through, in 40 minutes.

Cook the second batch by using the same method. After cooking the first batch, check the water level and add more if it runs too low.

Serve warm over steamed rice as a main.

Store the meatballs in an airtight container in the fridge for 3 days or in the freezer for up to 2 months. After steaming, the meatballs will render some fat and liquid. Drizzle it on the meatballs before storage, to keep the them tender and moist.

The best way to reheat the meatballs is by steaming, the same method used to cook them. The meatballs will be heat up evenly and still be moist inside.

Alternatively, you can use the microwave. Make sure the container has some liquid (leftover grease or 1 teaspoon water) inside. Please a loose lid on top and heat it up in the microwave.