In a large bowl or electric mixer, place your flour, eggs, sour cream and 1/2 cup of water. Beat the eggs and gradually add in the rest of the water until the mixture is completely combined. It will form a pretty sticky dough.
Once the dough is formed, lay it out on a floured surface and kneed it. You want to need it until the dough becomes smooth and only a tiny bit sticky. It takes about 5 minutes.
Wrap the dough in plastic wrap and let it rest on the counter for about 30 minutes.
Boil the potatoes. Start with cold water and your peeled/sliced potatoes. Bring it to a boil, reduce heat to medium and cook for about 20 minutes (until potatoes are tender).
While potatoes are cooking, melt the butter and oil in a pan over medium low heat. Add the minced onion and start to caramelize it over low heat. About 5 minutes before they are done, add the minced garlic.
Once the potatoes are soft, drain them and make sure you get out as much moisture as possible (I usually let them sit for a couple minutes).
Once the potato is thoroughly drained, add the onion/garlic mixture and the farmers cheese. Mash it together like you would mashed potatoes until totally smooth. Add salt and pepper to taste.
Bring large pot of water to a boil. Flour up your hands and take about a tablespoon sized portion of the dough and roll it into a little ball. Continue until all the dough is in balls.
Once you have all your dough balls, gently roll each of them out with a rolling pin. After you finish one, place it under a damp towel so it doesn’t dry out (very important).
When you have all your dough balls rolled out, hold each in the palm of your hand, add about a tablespoon of the potato filling and fold the dough in half. Pinch the edges firmly shut. After you complete them, cover them in plastic wrap on a well floured surface.
Once they are all made, working in batches drop about 5 pierogi at a time into the boiling water. They will float to the surface when they are done (takes about 3 minutes each). Remove with a slotted spoon and put on a towel to drain.
Finish them off! You could totally eat them boiled, but I like to heat a tablespoon or two of butter and sauté them up till the get golden and a little bit crispy!