Pierogi with bil-, blue- or strawberries recipe - original Polish recipes

Rinse fruits with water and wash it.Cut up 0.5 kg of strawberries into little pieces. Use fresh strawberries of good quality. Stale strawberries results in bitter aftertaste of pierogi and spoil the taste. We use the whole bilberries - don't cut them nor crush. Blueberries since those are larger might be used halved as I suppose (I never made pierogi with blueberries).Put cut strawberries in a bowl, whereas 0.5 kg of blueberries in second one. Pour few teaspoonfuls of sugar into bowls with strawberries and gently mix. Taste, whether the amount of the sugar is sufficient. You can add more, if you want pierogi to be really sweet. I usually give quite large amounts of sugar. Don't add sugar to bowl with bilberries since those tends to excrete too much too watery juice. Making pierogi is more difficult with such a mixture. Strawberries mixed with sugar should stand some time (in the meantime prepare pierogi dough). Thanks to that the sugar will manage to dissolve in the juice which will sail out of fruits. You can add a teaspoon of the potato starch into both bowl and then mix precisely. This is optional. Starch makes the fruit sauce within pierogi more dense after cooking.We prepare pierogi dough according to the standard recipe with is published at Tasting Poland. You can however try out some modification which I recommend: instead of boiling water use 0.75 of the cup of hot milk. The dough will have more delicate taste. That's the way some Poles prepare dough for sweet pierogi.Lay portions of blueberries on dough circles and add quarter to half a teaspoonful of sugar. Put portions of strawberry 'mousse' on other circles.Glue pierogi very carefully. It is important, since pierogi with fruits has a greater tendency of opening during cooking, than pierogi with any other filling.Put water with the addition of salt and the spoonful of oil on the cooker. Thanks to oil pierogi won't get glued to each other. After few minutes, when water starts boiling we throw pierogi, one after another. Stir every couple of minutes so that they don't stick to the pan. When the dumplings will flow to the surface we still cook 2-3 minutes. Take one pierog out and check, whether the dough is soft. If not - continue cooking for a while.Now drain pierogi, lay on plates and decorate with additions. A great freedom exists in choosing what we will pour over our pierogi. In general Poles use a sweetened cream or yoghurt (sweetened natural yoghurt or fruit yoghurt). You can sprinkle with brown sugar, as well as slices of raw fruits. Pierogi with fruits, in contrast with other kinds, is not refried on the frying pan. It is also very tasty when cooled off. Then it is possible to serve pierogi with addition of the whipped cream. Serving the cooled fruit dumplings with vanilla ice cream is another possibility. Obviously you can invent your own ways of serving too.