Mix all filling ingredients in a bowl. Allow it to marinate for 30 minutes.
Place one pot sticker wrapper on palm. Spoon 1 teaspoon filling in the center of the wrapper. Moisten wrapper around the edges with a finger dipped in water.
Fold wrapper into a half circle. Fold 6 to 7 pleats around the edge of the wrapper from one end to the other. Press to seal.
Place dumplings in a single layer on a flat plate.
Bring 8 cups (1.9 liters) of water in a pot to boil. Lightly scald choy sum. Remove, drain, and set aside.
Gently drop about half the dumplings into the pot. Reduce heat to medium and allow them to simmer for about 3 minutes. Cooked dumplings will float to the top. Remove and drain dumplings.
Place 1 stalk of choy sum and 3 dumplings in a bowl. Ladle some soup onto dumplings. Add some sliced green onions and a few drops of sesame oil to the soup. Serve hot with dumpling or soy sauce.
Alternatively, dumplings can be deep fried in hot oil until golden brown.
Another method is to pan fry and steam the dumplings. For this method, it is best to wrap dumpling in the more traditional crescent or ingot like shape.
Place one pot sticker wrapper on palm. Spoon 1 teaspoon filling in the center of the wrapper. Moisten wrapper around the edges with a finger dipped in water. Fold wrapper into a half circle. Fold 5 to 6 pleats around the edge of the wrapper from the center to the edge on one side. Do the same in reverse for the other side. Press to seal and shape into crescent.
Place dumplings in a single layer on a flat plate.
Heat 1 tablespoon vegetable oil in a large non-stick fry pan. Place half the dumplings in a single layer in the pan. Brown bottom and sides. Add ½ cup (120ml) water to pan and cover with lid. Steam fried dumplings until water has evaporated. Continue to fry until bottom is crisp. Repeat with the other half of dumplings.