Pour the flour on a counter or other surface that will allow you to make the dough
Add a pinch of salt
Make a little whole in a middle and start adding milk and butter
Add a little water at the time and work the dough until you can form a ball about 10-15 minutes
Once done, cover it with the big bowl and let it rest for about 20-30 minutes
Use ¼ of the dough at the time, covering the remaining with the plastic wrap
Roll the dough until thin (like pasta) and using either cookie cutter or large wine glass cut the circles
Place 1 teaspoon of fling in the middle of the circle
Wet one half of the circle and then seal it together
Boil large pot of water and season with salt
Once the water is boiling put about 8 pierogi at the time
Once they come to the surface let them cook for 1 minute and using spider or slotted spoon take them out on a plate
If you are not serving pierogi immediately, take them out on a counter and let them cool down and dry a little bit. Make sure that they are not touching each other. Once cooled, place them on a baking sheet, again with distance from each other, place in a freezer and let them freeze. Once done, you can pack them in the plastic bag.
Place dried mushrooms in a pot of water and let it stand, preferably overnight
The day of making pierogi, cook porcini mushrooms in the water that they soaked in
Rinse the sauerkraut and place in another pot, cover with water and cook for about an hour
In the meantime heat up 1 tablespoon of oil, add chopped onions and cook until soft, about 5 minutes
Add sliced fresh mushrooms to the onions and cook until soft, about 15 minutes
When dried mushrooms are cooked, remove them from the water with slotted spoon, reserve the water
Rinse them well under running water to make sure that they are perfectly clean
Once all your ingredients are cooked, you can add sauerkraut, fresh mushrooms and dried mushrooms to the food processor and process until finely chopped but not mushy
Placed processed filling back to the pan and using strainer add ¼ to ½ cup of dried mushrooms water and cook for a few minutes
Check for seasoning, add salt and pepper and cook for few more minutes until all the ingredients are merged.
Let it cool before starting to assemble pierogi.
Dried porcini mushrooms do the heavy lifting here, providing a concentrated punch of umami that fresh fungi simply cannot replicate on their own. Rehydrating them overnight draws out water-soluble compounds like glutamates, creating a potent soaking liquid that concentrates the earthiness of the entire filling when reduced in the pan. Rinsing the sauerkraut before cooking controls the lactic acid level, ensuring the filling remains pleasantly bright rather than overwhelmingly sharp against the buttery dough.
Dough Hydration and Rest Mechanics
Working warm milk and water into all-purpose flour initiates rapid gluten development during the required 10 to 15 minutes of manual kneading. Resting the resulting dough ball beneath an inverted bowl for 20 to 30 minutes relaxes those protein strands, making the sheet pliable enough to roll thin without snapping back.
Shaping and Thermal Processing
Rolling the dough until thin ensures the cooked pasta yields easily to the tooth without dominating the filling. Boiling requires a spacious pot so water temperature does not plummet when eight dumplings enter at once, signalling doneness precisely one minute after they float to the surface.