Step 1

Peel and quarter potatoes and bring to a boil in a large pot. While potatoes are cooking, grate cheese and sauté onion. When the potatoes can be easily pierced with a fork, drain and quickly return to the pot over the heat to remove any remaining water. Begin mashing with a potato masher, adding sautéed onion and cheese. Incorporate well and mash the potato mixture down into a hard-pack in a large bowl until flattened on the top. Let cool and place in the refrigerator overnight.

Step 2

In a medium sized bowl, measure unbleached, all-purpose flour using the scoop and sweep method  and sprinkle table salt on top. Make a well adding egg sour cream.

Step 3

With two knives, incorporate the egg and sour cream into the flour. Slowly add in approximately lukewarm water. (Add only a small amount at a time as you continue to cut the egg into the flour.) (My Mom is very particular and meticulous about this step. She goes slowly and makes sure every bit of flour is incorporated with the wet ingredients, so take your time here.) Once all the ingredients have been mixed, the dough will not be very smooth and possibly quite sticky. Use your hands to bring it together into a ball. Let the dough stand covered with an inverted bowl for approximately 1/2 hour before using. (Don't skip this, the dough needs to rest.)

Step 4

Once you have made all your dough batches take either all of a dough ball, or a portion of the dough, and roll it out until it is 1/16" thick. (Using flour will help you keep the dough from sticking to the rolling pin and rolling surface. Your available work surface will obviously dictate how much you can roll out at any one time. Thickness of the dough is very important for good pierogi.) Cut out circles as close to the dough edge as possible and place them on a clean dish towel, placing them flat, just as you cut them out of the dough. In other words, do not flip them over. Keep the circles covered with a dish towel as they dry out easily. (Leftover dough scraps after cutter can be put together into a ball and placed under a bowl to use at the end.)

Step 5

Remove only some of the filling from the large bowl in the refrigerator so that you can keep it cold. Place about 2 Tablespoons of filling into the dough circle.  Do this by picking up each circle and flipping it over into your hand. The edge on this side is better to seal. Place filling inside. (The dough stretches well as you press the filling in with a spoon.) Add more filling if necessary. Bring the dough together and crimp the edges with your fingers. (Be aware that if you have any filling on your fingers or on the edges of the dough, where you are trying to seal the edges, the dough will not close.) Also, be mindful not to make any small holes in the dough or leave any edges unsealed as they will come apart during cooking.

Step 6

Bring a large pot of water to a boil. Once water is boiling, place twelve pierogi at a time in the water. When they float to the surface, give them about one more minute and remove them from the water using a slotted spoon so the water can drain off. (It is common to lose a few at this point that have not been sealed properly (early snacks)). If it is happening a lot, reseal your other pierogi before dropping them into the water.

Step 7

Take them directly from the water and place them into a frying pan with a gob of melted butter over low heat. (Here you are basically just coating them well with butter so they do not stick to each other. (At this point you can cool them and freeze them in Ziploc bags if you like.)

Step 8

If you are going to serve them, I like to line them up like soldiers in a 9 x 13 pan and keep them warm in a 200 degree F. oven (covered).

Step 9

In a large frying pan, fry bacon until crispy, remove, leaving some of the fat to sauté onion.  When the onion is done, add the crispy bacon back to the pan and mix together.

Step 10

Sprinkle the bacon-onion mixture over your pierogi and serve warm.

Step 11

If you need to rewarm them the next day, place a dozen at a time in a large frying pan over low heat and cover. You are basically steaming them, but it's okay to make them a little crispy too. Serve with sour cream if you like.