Pyon Soo (Korean square dumpling) 

Filling : combine pork, kimchi, bean sprouts, onion, garlic, ginger, egg, soy sauce salt and pepper.

To a wanton skin, put a little bit of egg wash on the border and put  the filling about a tablespoon or so. Make wanton shape. You can make this square man doo(wanton) by bring up the four corners at the same time. Then pinch from the out side in, carefully shape to the center.

Boil a big pot of water, add man doo(dumplings). Once they come up to the surface, add 1/2 cup cold water. They come up again and get translucent, done! Serve with "cho kan jang (soy sauce with rice vinegar)".
Cho kan jang : 3 tbsp soy sauce + 1 tbsp rice vinegar

 cool tip !
You can be very creative with man doo (wanton). Skip the pork, use ground beef, turkey, chicken or combine any two or three. Or forget everything, just do vegetarian version. I'm not a vegetarian but sometimes without any meat can be very good.
There's one Korean street food called "Ddeok bok ee", very hot stewed rice cake dish,
most girl's favorite~, and with it, they sell fried dumplings that have almost nothing in it but dang myon(starch noodle), green onions and some seasonings. But they are good!!!
If you find it hard to make square, just use round wanton skin, fill the filling, fold it into a half, make a half moon shape regular wanton. To make it pretty, give some ruffles on the edge.
You can freeze them!!! Put one layer of dumping on a baking sheet and stick to a freezer. Be careful let them not to touch each other, because once they freeze it's hart to separate them without tearing the skin. After they freeze, store in a zipper bag, put back in to a freezer.