Boil potatoes until soft.
Drain then mash the potatoes and add the sautéed onions and 1/2 cup grated cheese. Season with salt and pepper to taste.
Blend the Chebe mix with the eggs, milk and oil as per package instructions.
Mix for a couple of minutes with a fork, then knead dough with hands until smooth. If too dry, add 1 tsp water.
Place between two pieces of wax paper* and roll out to approximately 1/8" thickness. (You may spray the paper with cooking spray.)
Cut dough into 5 inch circles. Place 1 Tbsp of filling into each circle of dough. Fold over into semicircles and crimp edges tightly. Avoid letting the filling touch the edges of the circle as it will make crimping more difficult. (May use a dough press).
Drop pierogies into a pot of boiling water with a little oil to prevent sticking. Boil for 3 minutes or until they float. Remove from pot with a slotted spoon and drain on a paper towel or in a colander.
*An alternative to using waxed paper is to dust a clean dry surface with gluten free flour our starch. Then, use the rolling pin to gently roll to the desired thickness. While pressing flat, dust the top of the dough with the flour and flip it. Continue pressing until it is 1/8" thick.
You can eat the pierogies immediately or freeze them to eat later.