Place the grated potatoes in a clean kitchen towel and squeeze out any excess moisture.
In a large bowl, combine the grated potatoes, chopped onion, beaten eggs, flour, salt, and black pepper. Mix well until all the ingredients are evenly incorporated.
Heat a large skillet or frying pan over medium heat and add enough vegetable oil to cover the bottom.
Take a spoonful of the potato mixture and drop it onto the hot skillet, flattening it slightly with the back of the spoon. Repeat to make additional pancakes, leaving enough space between them in the pan.
Cook the pancakes for about 3-4 minutes on each side, or until they are golden brown and crispy. You may need to cook them in batches, depending on the size of your pan.
Once cooked, transfer the pancakes to a plate lined with paper towels to absorb any excess oil.
Serve the potato pancakes hot with lingonberry sauce or sour cream, if desired.
