In a large bowl, mix the flour and salt. Add the egg, sour cream, and warm water. Stir until a dough forms. Knead for about 5-7 minutes until smooth. Cover and rest for 30 minutes.
In a bowl, combine flaked roasted salmon, cream cheese, dill, green onions, lemon zest, salt, and pepper. Stir until smooth but still slightly chunky.
Roll out the dough on a floured surface to about 1/8-inch thick. Cut out rounds (about 3 inches). Place a heaping teaspoon of filling in the center of each. Fold over and pinch the edges tightly to seal.
Bring a large pot of salted water to a boil. Add pierogi in batches and cook until they float (about 3-4 minutes). Remove with a slotted spoon.
Optional – Pan-Fry: Heat butter in a skillet and pan-fry the pierogi until golden on both sides.
Drizzle with melted butter and serve with sour cream and fresh dill.
Notes
Keep the dough soft and slightly sticky – a softer dough makes more tender pierogi. Don’t over-flour when rolling it outChill the filling – cold filling is way easier to work. Don't overstuff – stick to about one tablespoon per pieróg.Cook in batches – don't overcrowd the pot. Boil them gently in small batches.