In a skillet, heat the vegetable oil over medium heat. Add the chopped onion and cook until translucent.
Add the ground pork or beef to the skillet and cook until browned. Season with salt and pepper. Set aside to cool.
Grate the potatoes and place them in a large bowl. Squeeze out excess moisture using a clean kitchen towel.
Add the egg, flour, and salt to the grated potatoes. Mix well until a dough forms.
Take a portion of the potato dough and flatten it in your hand. Place a spoonful of the meat filling in the center, then carefully fold the edges over to seal the filling inside. Shape into an oval or football shape. Repeat with the remaining dough and filling.
Bring a large pot of salted water to a boil. Gently drop the prepared dumplings into the boiling water. Cook for about 20-25 minutes, or until the dumplings float to the surface and are cooked through.
In a saucepan, heat the vegetable oil over medium heat. Add the chopped onion and cook until translucent.
Stir in the flour and cook for 1-2 minutes. Gradually add the sour cream, stirring continuously until the sauce is smooth. Season with salt and pepper.
Remove the cooked dumplings from the water and drain. Place them on a serving plate and pour the sour cream sauce over the top.
Enjoy your meal!