Bring a large pot to a boil, salt with water to taste. Peel the potatoes and cut into quarters. Add to water along with bay leaves and cook uncovered on medium heat until fork tender. About 10-12 minutes.
Remove from heat, drain water and remove bay leaves.
Add butter and mash until smooth. Add milk and using a spoon whip the potatoes until combined.
Add milk and butter pieces into a pot and heat until butter melts on low heat. Mix to combine. Let cool for 5 minutes.
In a bowl add flour, salt and 1 egg, whisked. Slowly add in the slightly cooled milk and butter mixture. Stir to combine.
Once dough is formed, add some flour on your countertop and knead the dough for 2-3 minutes.
Set the dough aside and cover to rest for 10 minutes.
Once you are ready to make your first batch of vareniki, divide your dough into 3 pieces. Cover the pieces you aren’t using.
Roll out the dough thinly on a floured surface to just under ⅛” thickness. Using either glass or a 3 inch cookie cutter, cut out round shapes. Keep the shapes as close as possible, keeping the scraps (add them to the unused dough to reuse).
Add ½ Tbsp of potatoes over each round piece of dough, fold over in half and pinch together to seal and make a half moon shape. To ensure a tight seal, crimp the edges a second time with a pinch and twist motion.
Place the prepared vareniki on a floured baking sheet to prevent sticking.
If making ahead, you can freeze them and once frozen on the floured baking sheet, add to a freezer bag and store until ready to use.
Bring a large pot of water to a rolling boil and add kosher salt to taste. Carefully add fresh or frozen vareniki once water has boiled.
Cook for about 10-12 minutes, then once the vareniki are floating and water is back to a boil, the dough should be very tender. Carefully remove to a bowl with a slotted spoon. Add butter and gently toss to combine. Add to a bowl, top with sour cream and fresh dill or green onions and enjoy. Or kick it up a notch and cook up some caramelized onions and bacon to add as a topping along with sour cream and fresh herbs.
