These traditional Polish dumplings are fairly easy but pretty time-consuming to make. For me, their rich woodland flavours make them the perfect street food for making on a wild, wet autumn afternoon – they really are comfort food extraordinaire .
To make the dough, stir the flour and salt together in a large bowl. Pour in 200ml water and add the soured cream or yogurt, stirring to bring it together into a flaky ball. Tip on to a lightly oiled worktop and knead for 5 minutes until smooth and shiny. Wrap in cling film and chill in the fridge for an hour or so (up to 24 hours is fine).
Meanwhile, melt 25g butter and 1 tablespoon olive oil together in a large frying pan set over a medium-low heat. Add the chopped onion and allow to soften and lightly caramelise for 10–15 minutes. Stir through the grated potato, mushrooms and caraway seeds and season well with salt and pepper.
Tear off a sheet of baking parchment and scrunch it up under running water. Shake off the excess water and spread it out over the filling in the frying pan, tucking it snuggly around the edges to create a steamy lid. Reduce the heat to low and cook gently for a further 15 minutes until the potato is soft and collapsing, stirring occasionally to incorporate the caramelised bits on the base of the pan. Turn off the heat, scoop this filling mixture into a dish and leave to cool.
Wipe out the frying pan and set back over a medium heat. Add the remaining oil and fry the bacon until crisp on both sides. Set aside to drain briefly on a plate lined with a couple of sheets of kitchen paper, then snip into pieces. Add the sliced onions and remaining 50g butter to the pan and gently fry until soft and lightly caramelised, about 20 minutes. Scoop into another dish and set aside. Give the frying pan a wipe clean.
Take the ball of chilled dough from the fridge and roll it out on a lightly floured worktop until it’s about 2mm thick. Take a 10cm cutter and stamp out as many circles as you can, then re-roll the scraps and cut a few more circles until you have used as much of the dough as possible.
To fill the pierogi , take one circle and place a heaped teaspoon of filling on one side, leaving a border around the edge. Dampen the border with a little cold water using a clean finger or small brush. Fold the other half of the circle over the filling, pressing the edges together to seal the filling inside, then crimp and roll the edges over so they look like miniature pasties. Set aside on a well-floured baking tray. Repeat until you have used up all the circles and filling.
When you are ready to cook, bring a large pan of lightly salted water to the boil over a high heat. Add about a third of the pierogi and simmer rapidly until they all bob to the surface, about 4–5 minutes. Scoop out with a slotted spoon, allowing the water to drain back into the pan, and tip them on to a lightly oiled baking tray. Cook the remaining pierogi in 2 more batches, placing them on to the baking tray in a single layer when done – use 2 sheets if necessary so they don’t stick together.
Add a little butter to the cleaned frying pan and let it melt over a medium heat. Fry the pierogi in batches for a minute or so on each side until crisp. Then transfer to a dish and keep warm in a low oven (around 110°C/90°C Fan/Gas Mark ¼). Once all the pierogi are fried, tip the onions back into the pan to warm through, along with the bacon. To serve, divide the pierogi between plates, spoon over a few onions and bits of bacon, drizzle on a little soured cream and scatter with a few chives.