Add the warm water, egg and 2 Tablespoons melted butter. Mix until a dough forms.
Knead the dough on a flat working surface for 4-5 minutes until the dough is smooth and easy to work with.
Place the dough in a bowl, cover it and let it rest at room temperature for at least 30 minutes.
For the Filling:
Peel and boil the potatoes until fork tender. Drain the potatoes and mash them.
In a skillet, cook the sliced white onion in the remaining butter until soft.
Stir the cooked onion, shredded cheddar cheese, salt and pepper into the mashed potatoes.
To Assemble:
Roll the dough out until it’s approximately 1/8 inch thick. Cut the dough into 3 inch circles with a round cookie cutter or biscuit cutter.
Scoop approximately 1 Tablespoons of the potato filling and roll the mixture into a ball. Place each of the ball fillings onto each of the dough rounds. Fold the dough over to form a half circle and pinch the edges together to seal them close.
Continue this process until all the pierogies are formed.
To Cook:
Heat 2 Tablespoons butter in a large skillet over medium high heat until melted. Stir in sliced onions and cook for 3-4 minutes until the onions are tender. Remove the pan and set aside.
Bring a large pot of water to a low boil. Carefully add in the pierogies and cook until they float (approximately 2-4 minutes). Make sure to not crowd the pan. You will likely need to cook in batches.
Once boiled, add the pierogies to the skillet with the melted butter. Sauté for approximately 5 minutes per side until lightly browned.
Remove from the skillet, warm warm with the onions and sour cream (if using). Enjoy!
Video
Notes
When making the pierogies, make sure to securely pinch the seams together and make sure that this seam is not too thick and that it's thin like the remaining dough. I find that Russet or Baking potatoes work the best for the filling in this recipe. Shred your own cheese for the best consistency of the potato filling in these homemade Perogies. Refrigerate any leftovers in an airtight container for up to 5 days