Heat butter in a skillet and saute onions until soft but not golden. Remove to a bowl and mix with mashed potatoes, cottage and cheddar cheeses.To fill: Take out a few wrappers, leaving others under a cloth to keep moist. Center a teaspoonful of filling of your choice on wrapper. Fold dough over the filling to form a semi- circle. Brush bottom edge of semi- circle only with water and press top edge over the top. Pinch the edges together well so that they come together. You can make top "pleats" or not, as you wish. Repeat with the other wrappers until you have created as many "stuffed pastas" as you wish. Freeze on trays, then stack in freezer bags, in portion sizes which make sense for your family. You can boil them straight from the freezer.
To boil the meat stuffed pasta: Bring 2 cups each water and chicken broth to a boil. Add 2 grated carrots, 1 cup shredded bok choy or cabbage and simmer 2 minutes or until vegetables are tender. Add meat dumplings and cook gently so filling does not explode for 3 to 4 minutes or until meat is cooked through. Serve with a ladleful of broth and vegetables, garnish with sliced scallion of chives. . To saute meat dumplings: Heat 1 tablespoon each of sesame and vegetable oil in 12-inch skillet. Add 12 dumplings and saute until crisp on one side, about 5 minutes. Cover and steam another 2 minutes or until filling is cooked through. Remove to a plate; fry more if needed. Serve with a sauce of soy mixed with rice vinegar, sugar and scallion. Note you can also deep fry them for about 2 to 3 minutes or until golden. To boil potato stuffed pastas: Boil in salted water for 7 to 8 minutes or until they float to the top. Drain and serve with melted butter and or sour cream and chopped chives.
To fry potato stuffed pastas: Saute in a mixture of butter and oil for about 3 minutes per side or until each side is delicately crisp and interior is hot. Serve with butter and grated cheese or sour cream and more cottage cheese.