Mix flour, 1/2 teaspoon salt, sugar and baking powder in a bowl. Add butter, 2 eggs and 200 g sour cream. Knead everything to a soft, not sticky dough. If necessary add some more flour.
Wrap in foil and chill for about 30 minutes.
For the filling, peel and finely dice the onion. Heat the oil in a pan and fry the minced meat until crumbly. Add onion, fry briefly, season with salt and pepper. Add stock and simmer for about 5 minutes.
Remove from heat, season again and let it cool down.
Roll out the dough in portions on a floured work surface until it is about 5 mm thin. Cut out circles of approx. 8 cm Ø. Knead the rest together again and roll out again until the dough is used up. Place 1 heaped teaspoon of filling in the middle of each circle of dough.
Fold up, press the edges together.
Spread on 3 baking trays lined with baking paper with the seam facing downwards. Whisk 1 egg, brush the dough with it. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see
manufacturer) Bake for 15-20 minutes.
For the dip, drain the cucumbers and collect some stock. Dice cucumbers, wash dill, dab dry and chop finely. Mix 300 g sour cream with dill and cucumber. Season to taste with 2-3 tbsp. stock, salt and pepper.
Remove the dumplings from the oven, serve with dip and the remaining minced meat.