Filling: Place potatoes into a pot, and cover with water. Bring to a boil, and cook until tender, about 15 minutes.
Drain and place in mixing bowl. Add soy milk and vegan butter. Mash well or beat with an electric mixer until fairly smooth. Set aside.
Dough: In a large bowl, place the flour. In a separate small bowl, whisk together the butter, sour cream and oil.
Stir the wet ingredients into the flour until well blended. Cover the bowl with a tea towel, and let stand for 15 to 20 minutes.
Separate the dough into two or more balls. Roll out one piece at a time on a lightly floured surface until it is thin enough to easily work with, but not so thin that it tears when folded.
Making the perogies:Cut into circles using a cookie or biscuit cutter. Spoon 1 tablespoon of filling into one side of each perogy. Pick up perogy and fold over and seal with your hands. Place perogies on a cookie sheet until all are ready to be cooked.
To boil perogies: Bring a large pot of water to a boil. Drop perogies in a few at a time. Stir them gently a few times to insure they don't stick to each other or the bottom. Boil for a minute or two. They're done when they float to the top. Remove with a slotted spoon' drain well in a colander and serve hot.
To fry perogies: heat oil over medium heat in a skillet. Place 6 to 8 perogies in the pan. Fry for a minute or two on each side, pressing them slightly as they cook. Watch them as they cook very quickly.
Once cooked, remove from heat and serve immediately.
Serve perogies with sour cream and fried onions.
