1. prepare a large bowl with cold water.
2. Peel the potatoes and onion. Grate the potatoes and onion and transfer to the cold water.
3. Drain the liquids and then wrap grated potatoes and onion with cheesecloth or kitchen towel, twist cheesecloth into a pouch and squeeze out excess liquids.
4. Transfer to a large bowl, add salt, pepper, flour and beaten eggs. Mix well.
5. In a large skillet heat oil over medium-high heat. spoon 2-3 tablespoons of potato mixture the hot oil, flatten slightly.
6. Fry 3-4 minutes on each side or until golden brown. Transfer to paper towels to drain and season with salt.
7. Serve with sour cream.