For the dough, mix your flour, egg, and salt in a large bowl. Add 1/3 cup water and mix the ingredients together using a spoon (you can switch to using your hands at the end of the mixing). You want the dough to be wet enough that it's not too dry but not so wet that it sticks to your hands. You can add small amounts of extra water to the dough to get it to that happy medium if you need to. Roll the dough into a ball, wrap with wax paper (to keep it from drying out), and place into a bowl and refrigerate for a few hours or overnight. Once the dough has chilled, separate the dough into 12 small balls about the size of a golf ball and lay them on a clean dish towel.

The filling can also be done a day ahead as well (although it doesn't have to be). Peel and cube the potatoes, and boil in salted water until soft (just like you would for mashed potatoes). Once soft, drain the excess water and return potatoes back to the pot you cooked them in. Add the butter, cheese, and a little salt and pepper while the potatoes are still warm, and use a potato masher* to mix then all together. You are basically trying to create a really cheesy mashed potato for your filling, so keep tasting your potatoes, and add more cheese if needed. You want them to be a little too cheesy so that when they are covered in the plain tasting dough they will be just right. Refrigerate the filling until your dough is properly chilled.

*Note: We used a food processor to mix our potatoes because I realized last minute that we didn't have a manual potato masher at the studio. They definitely still tasted great, but I would suggest sticking with a manual masher for this recipe. I like the filling best when it isn't totally smooth and still has a bit of potato texture to it.

Flatten the dough balls with the palm of your hand and let them rest a few minutes to warm up. Flatten them again a little bigger and let them rest again. Repeat this process 1-2 more times until you feel the dough is warm and pliable (you can see in the photo above how much bigger they get each time you flatten them).

Dust a clean and flat surface with a tiny bit of four, and use a rolling pin to roll out your dough into a larger circle. The dough should have a nice stretch to it, but be careful not to use too much flour or the dough won't stick together when you try to seal the pierogi closed (believe me, you really only need a tiny bit).

Roll out the dough as thin as you can and then add a heaping spoonful of the potato filling in the middle of your dough circle. Fold the dough in half over the filling and press the edges together to seal the dough shut.

Boil a pot of salted water that's big enough to hold several pierogies at once, and add 2-4 perogies at a time to the boiling water. Let them bounce around in the water for a few minutes (this part is actually cooking the dough) until they float across the top of the water. This step is why you really need the pierogies' edges to be sealed, or they will open up during this boiling process. Remove with a slotted spoon and place in a colander to drain the excess water. Once drained, move the pierogies to wax paper until you're ready to fry them, but don't let them touch each other until after they are fried, or the dough will really stick together.

Add a teaspoon of butter to a pan over medium heat, add several perogies to the pan, and begin to fry them. Once the dough has turned a beautiful golden brown, flip the pierogi over and brown the other side. Repeat the process with all your pierogies, but keep an eye on the heat of your pan. If your butter burns as soon as you put it in the pan, the heat is on too high, and you'll want to wipe out the burned butter and turn your heat down before starting again. Once all your pierogies are fried, add your garnishes, and you're ready to serve!