Using a food processor or box grater, coarsely shred the peeled potatoes along with the onion. Wrap the grated mixture in a clean kitchen towel or cheesecloth, then twist and press firmly to extract as much liquid as possible.
Place the dry potato-onion mixture into a large mixing bowl. Add in the eggs, flour, salt, and black pepper. Stir thoroughly until the components are fully integrated and the mixture holds together.
Warm a large skillet over medium heat and add enough oil to form a thin coating across the base. Allow the oil to heat until it begins to shimmer.
Spoon approximately 1/4 cup of the prepared batter into the skillet for each pancake. Lightly press the mound down with a spatula to flatten into a round shape.
Cook the pancakes for 3 to 4 minutes per side, or until each side develops a golden-brown crust and is cooked through.
Transfer the finished pancakes to a paper towel-lined plate to drain excess oil. If preparing multiple batches, keep them warm in an oven set to 200°F (90°C) until all are ready to serve.
Present the pancakes hot from the skillet, accompanied by traditional condiments such as applesauce, sour cream, or your garnish of choice.