The recipe for fried wan tan comes from northern China.
Defrost wan tan dough sheets at room temperature. Mix egg with salt. In a non-stick frying pan, heat 1 tbsp soybean oil and fry egg to form an omelet. Remove from frying pan and chop into small pieces. Cut green onion into very fine rings. Remove peel from ginger and chop finely. Put pork steak and shrimp through a meat grinder or chop very finely. Mix all ingredients in a baking bowl and season with soy sauce and sesame oil.
Spread 1 tsp of the mixture evenly in the center of each wan tan pastry sheet. Mix maizena (cornstarch) with a little cold water and thinly coat the edges of the wan tans with it. Fold wan tan into triangles. Press edges smooth. Brush tips with the mixed cornstarch and fold all tips over to the center.
Press gently to smooth.
Heat remaining soybean oil in a wok or frying pan. Toast wan tan on medium heat for about 2 min on each side. Spoon 2 tbsp water over wan tan form (be careful not to splash) and place a lid on the spot. Turn heat up briefly so water evaporates.
Bring fried wan tan to table with sweet and sour sauce.