To Make the Dough: Sift the flour into a very large bowl. With your hand, form a well in the center of the flour. Add in the hot water, salt and oil. Using a fork, begin to bring the flour into the wet ingredients.

Once the mixture becomes like a thick paste, use your hands to knead the dough just until the flour is fully hydrated. Add the whisked egg and knead the dough for 5 to 6 minutes more until it becomes smooth. Cover the dough and let it rest for 30 to 60 minutes.

While the dough is resting, make the Potato & Cheese Filling: Add the potatoes to a pot of boiling salted water. Cook for 6 to 8 minutes or until tender. Do not overcook. Drain and mash the potatoes using a hand masher or a food mill.

Fold in the butter and cheese. Mix well to combine. Season to taste with the salt & pepper. Cover and set the filling aside.

To Form the Pierogi: Lightly dust a clean work surface with flour. Cut the rested dough into two equal parts. Roll out the first piece of dough until it is about 1/8” thick. Using a 3" to 3 ¼" round cookie cutter, make as many rounds on the dough as you can.

Place about 1 ½ tablespoons of the potato filling in the center of a dough round. Hold the topped dough round in the palm of your hand. Gently pull the edges of the dough to make it slightly larger as you cup your hand. Fold one side of the dough over to the other, covering the potato completely. Pinch the seams to completely encase the filling.

To be certain that they are sealed, gently press on the edges of each pierogi with the floured tines of a fork. Repeat the process until all of the dough and potato filling is used.

If cooking and enjoying right away: In batches, add the pierogi to a large pot of lightly boiling salted water. Cook until they float to the surface, which takes about 2 to 3 minutes. It is important that you cook the pierogi in batches. They are very tender and need space as they simmer.

While they have about 30 to 45 seconds left to cook, melt 3 to 4 tablespoons of butter in a large non-stick skillet over medium heat.

Drain the pierogi and add them to the pan of melted butter. Sauté on each side for 1 to 2 minutes or until lightly browned. Season to taste with salt. Garnish them with caramelized onions and optional chopped fresh dill fronds & chives. Serve any extra sautéed onions on the side along with an offering of sour cream.

For the sautéed onions: Add 4 tablespoons of butter to a medium-sized frying pan over medium heat. Sauté the onions for 4 to 5 minutes or until they begin to turn brown.

Turn the heat down to low-medium. Continue cooking for 10 to 12 minutes or until darker brown, tender, and translucent. Set them to the side.

If planning to enjoy at a later date, Freeze The Uncooked Pierogi: Place the uncooked pierogi in a single layer on a parchment lined baking sheet. Be sure that they are not touching each other. Sprinkle with a light dusting of flour and cover. Place the tray in the freezer.

Once the pierogi are completely frozen, which will be at least overnight, transfer them from the tray to a freezer storage bag. They can be safely frozen for up to 3 months.

When ready to enjoy, remove the desired amount from the bag and proceed with Step 4 by adding the frozen pierogi directly to the simmering water. It will take them slightly longer to float to the surface since you're starting off with frozen pierogi. Do not defrost before cooking as they tend to stick together before cooking.

OR to enjoy at a later date, Freeze the Cooked Pierogi: Follow the directions in Step 4 by adding the formed pierogi, in batches, to a large pot of lightly boiling salted water. When they float to the surface, transfer to an ice bath. When cooled, drain them and place them in a single layer on a parchment lined baking sheet. Be sure that they are not touching each other. Brush each one with a light coating of butter or oil. Place the tray in the freezer.

Once the pierogi are completely frozen, which will be at least overnight, transfer them from the tray to a freezer storage bag. They can be safely frozen for up to 3 months.

When ready to enjoy, remove the desired amount from the bag and place them in a single layer on a parchment lined tray. Allow them to defrost at room temperature for 2 to 3 hours.

Just before serving, melt 3 to 4 tablespoons of butter in a large non-stick skillet over medium heat. Sauté on each side for 2 to 3 minutes or until lightly browned. Season to taste with salt. Serve immediately with desired toppings.