Wash and dry the blueberries. Set aside. Mix sugar and flour in a small bowl. Set aside.

In a medium bowl, mix flour and salt. Make a well in the middle of the flour and crack the egg into the well. Mix the egg into the flour until it is evenly distributed.

Add the milk and mix until evenly distributed. Add the water 1-2 tablespoon at a time, mixing after each addition, until a smooth and soft dough forms.

Roll the dough out to ⅛” thickness.

Fill a medium saucepan with 2 quarts of water. Add salt and oil (the oil will help the pierogi from sticking together as it cooks). Cover and bring the water to a boil

While your water comes to a boil, fill your pierogi. Using a 3 ½ ” cookie cutter (or the mouth of a glass or jar, anything that is roughly 3 ½ inches) cut circles out of the dough. Re-roll the dough scraps as needed until all the dough has been cut.

Place about a tablespoon of berries on each round of dough. Sprinkle ¼ teaspoon of the sugar and flour mixture over the berries. Moisten the edge of each dough circle with a little water and fold the dough over the filling. Pinch the edges firmly to create a tight seal.

Once you have 5-8 pierogi filled and sealed, drop them into the boiling water. Boil the pierogi until the dough is tender, 7-10 minutes.

Using a large, slotted spoon, remove your cooked pierogi from the boiling water and place onto a plate. Continue with the remaining pierogi.*

Mix the yogurt with sugar to taste. Serve the pierogi topped with the sweetened yogurt, or use the yogurt as a dipping sauce.