Peel the potatoes and the onion.
Finely grate one potato and the onion into a bowl and mix well. Grate the remaining potato adding them to the mixture. (Please note the secret to this recipe is how finely you grate the potatoes and onion, it should be a pulp like consistency.)
Mix well, beat the egg, season it with salt and add it to the mixture.
You can add a couple teaspoons of water if you would like your pancakes to be a bit crispy which I would highly recommend.
Heat up the pork fat on high in a skillet and use about 1 tablespoon of mixture per fritter.
Fry until golden brown on each side.
Serve immediately and enjoy with sour cream.