For the filling
50g smoked bacon, finely chopped
1 small onion, finely chopped
1 small carrot, finely chopped
400g pork or beef mince
For the pierogi dough
360g plain flour, plus extra for rolling
240ml hot (not boiling) water
1tsp vegetable oil
3 smoked streaky bacon rashers
1tbsp vegetable oil
sour cream, to serve, optional
To make the filling, melt the butter in a saucepan and add the bacon, onion and carrot. Cook for about 8 minutes, until the onion is soft, but not coloured. Cool then stir into the pork or beef mince with plenty of black pepper and a little salt.
To make the dough, measure the flour into a large bowl and make a well in the centre.
Crack the egg into the well with the hot water, salt and oil. Quickly beat the wet ingredients with a fork then slowly incorporate the flour, until a soft dough forms.
Knead for about 8 minutes until smooth and elastic, adding a little extra flour if it sticks. Divide the dough into thirds and keep covered.
Roll the first third out on a lightly floured surface, until it is an even 3mm thick. Using a plain, round 7cm cutter, stamp out about 12 circles. Keep the finished circles covered with a slightly damp tea towel to prevent them drying out. Repeat with the remaining two lots of dough to make about 36 circles.
To fill, cup a circle in your palm, and put a packed teaspoonful of filling in the middle.
Lightly wet the edges with water and pinch together tightly to seal. You can fold the edges over or crimp them with a fork if you wish.
Keep the surface dusted with flour and cover the finished dumplings with a tea towel to prevent them them drying out.
Grill the bacon rashers until crisp, then cool and crumble into shards.
Heat the remaining butter and vegetable oil in a large frying pan and brown the pierogies, in batches, on both sides. Serve sprinkled with crisp bacon shards, with sour cream, if liked.