Peel and grate the potatoes and onion
Press the liquid out from the grated potatoes and onions using a mesh strainer.
Combine the grated potatoes, onion, flour, egg, salt, and pepper in a bowl.
Take one heaping spoonful of the mixture at a time and press it flat using the back of a second spoon.
Place the flattened spoonful onto the preheated frying pan with oil sizzling hot.
Use the back of a spoon to flatten and spread the pancake even thinner on the pan to get a crispier pancake.
Fry each side for 3 minutes over medium heat, until golden brown on each side.(Thicker pancakes may take a little longer to cook through, so you may need to lower the heat to allow the time needed.) Complete the frying process with all the pancakes. Add additional oil as needed if the pan gets too dry.
Remove the finished pancakes to a paper towel lined plate to remove some of the oil.
If you want to keep them warm until all the potato pancakes are ready, you can put them in a 200 degree oven while finishing the entire batch.