MAKE THE FILLING:

1. Add potatoes to a medium-sized pot. Cover with water, add 2 tsp. of salt, and bring to a boil. Cook for 20-30 minutes or until they can be easily pierced with a fork.
2. Drain the potatoes in a colander. Return the pot to the stove.
3. Add butter to pot and melt over medium-high heat.
4. Add garlic and onion to pot. Sauté 3-4 minutes, stirring occasionally, until onion is translucent.
5. Add salt, pepper, and dried thyme to pot and stir to combine.
6. Return potatoes to the pot with the onion mixture and mash with a potato masher until potatoes are relatively smooth.
7. Add fontina and parmesan cheeses to potato mixture. Stir until cheese is melted.
8. Let your potato mixture cool for at least 30 minutes before you form the pierogi. You can also let them cool completely and store in an airtight container in the fridge for a few days until you're ready to make the pierogi (makes for less work later!)

MAKE THE DOUGH:

1. In the bowl of a stand mixer fitted with a paddle attachment (or in a large bowl), mix flour, eggs, salt, and sour cream together.
2. Add 1-2 Tablespoons of water at a time to your flour mixture, mixing dough (or kneading with your hands) in between each addition. Dough is done when it comes together and feels relatively smooth but not sticky.
3. Turn dough out onto a lightly floured surface. Cover with a tea towel and let rest for 30 minutes. (If you're making the dough ahead of time, wrap it tightly and store in the fridge for 1-2 days. When you're ready to use it, let it come back to room temperature on the counter before you roll it out).

FORM THE PIEROGI:

1. Set a small dish of room-temperature water next to your workstation.
2. Roll dough with a rolling pin or pasta roller until it's about 1/8" thick (I roll to the "2" setting on my pasta roller).
3. Cut dough into circles with a 2-3" cookie/biscuit cutter or an upside-down water glass.
4. Put about 1/2 tsp. of filling in the center of each dough circle. Dip a finger or a pastry brush into your dish of water and run it along the edges of the dough - this will help form a tight seal.
5. Fold the top of the dough circle over the filling and pinch the ends together with your fingertips to seal the pieróg. I like to start pinching the dough together in the center of the arch and work my way to the edges – this gives me more control over the edge and lets me make a scalloped (ish) finish. It takes some practice – take a look at the pictures in this post for some guidance, and don’t give up!
6. Transfer formed pierogi to a lightly floured sheet pan or cutting board. Cook immediately or cover and store in the fridge for up to 24 hours. If you're making them more than a day ahead of time, place pierogi in a single layer on a floured baking sheet and freeze, then transfer to an airtight container for up to 4 months (more tips on this in the body of this post above!)

COOK THE PIEROGI:

1. Bring a large pot of water to a boil and add a Tablespoon or so of kosher salt.
2. Add 5-6 pierogi to the boiling water and cook for 4-5 minutes until cooked through. You'll know the pierogi are done when you give them a stir and they float to the top.
3. While the pierogi boil, heat a Tablespoon of ghee in a large nonstick skillet over medium-high heat.
4. When boiled pierogi are ready, use a slotted/spider spoon to transfer pierogi to hot skillet. Fry for about 2 minutes per side until lightly browned, then transfer to a plate or serving dish.
5. Repeat steps 2-4 with remaining pierogi.
6. Garnish cooked pierogi with fresh chopped chives and serve immediately with sour cream, sauerkraut, or a quick sour cream chive sauce.