Take the half of the potatoes and grate them finely, set aside.
In a large saucepan, bring water to a boil, add the remaining potatoes and boil in their skins for around 25 minutes, drain and set aside.
After they cool down, remove the skins and grate them finely, combine with the raw grated potatoes, mix well and season with salt and pepper, set aside.
In another large saucepan place water with a little salt and bring it to a boil, add the beef and boil for around 40 minutes or until tender. Remove the meat from the pan and mince,
then combine it with the onions.
Take some of the potato mixture and shape into a small cake, fill with some meat mixture, fold over and re-shape into a pattie. Repeat the process with the rest of the ingredients.
Fry in melted pork fat until golden brown, around 12 minutes. Serve hot.