1. In a mixer, combine all-purpose flour, butter, eggs replacers, sour cream, salt, and water. Form dough into disk and wrap in saran wrap. Refrigerate for 1 hour.
2. Just before hour wait is up, in a medium skillet on medium-low heat, add the olive oil. Saute the onions until translucent and soft, about 10 minutes. Take dough out of fridge, dust counter with flour, and roll out dough with a rolling pin to about 1/4" thick.
3. Cut dough into 4 pieces. Roll each piece out until it is just a couple millimeters thick. Cut circle with cookie cutter that is about 2" wide. Add cheese and cooked onions to mashed potatoes. Mix well.
4. Place about 1 teaspoon mashed potato mixture in the center of circle. Dip finger in cold water and wipe more than half around the edge of the circle. Fold over and press all the air out sealing the edges. Use a fork to crimp the edges.
5. Freeze overnight on wax paper on a baking sheet so they do not stick. Once frozen, place them in a freezer ziplock bag. To cook, fry in olive oil for 5 minutes on each side until golden brown, grill on grill pan 5 minutes on each side, or bake at 350 degrees F for 15-20 minutes until golden brown.
I've had bad experience boiling homemade pierogies, so I wouldn't take that route, but you could try to boil them until cooked, 6-7 minutes.
Source of recipe: I wrote the recipe. For more information, please see my blog here: http://veganmiss.blogspot.com/2011/09/homemade-grilled-potato-onion-chee... [2]