Steam potatoes in their skins until tender. Allow to cool before peeling, and set aside.Whisk the eggs in the water. Add a pinch of salt to the flour in a large bowl, and slowly add the water and egg mixture to the flour. Use your hand to knead the dough to bring it together. Knead on a clean work bench into a smooth ball. Place in your bowl, cover and set aside for 20 minutes.Meanwhile, press your potatoes through a ricer in a large bowl. Add the butter, ricotta and a pinch of salt. Use your hands to mash the potato, combining all of the ingredients. Taste and adjust the seasoning.Half the dough and roll out on a floured surface to ⅛ inch thick. Use a 4 inch cutter to cut out disks, reroll the dough and continue to cut out until all of the dough is used. Add 1 tablespoon of filling to the centre of each disk, fold over and press the edges together to seal.Boil the pierogi in batches for 4-6 minutes (once the pierogi float continue to boil for 3-4 minutes). While the pierogi are cooking, warm the butter, caramelised onions and bacon in a frying pan. Pour the butter sauce over the pierogi to serve. Recreate global street food favourites with chef Dan Hong in on SBS Food.