You will need: 

1.5lb (~675g) of yellow Yukon Gold style potatoes 
Frying oil
Two pinches of salt 
One egg
Potato starch

Steps

1. Cut off any bad parts of your potatoes, shred them on a mandolin or box grater and immediately dunk them into cold water to prevent oxidation. 

2. Take a clean tea towel, and a fist sized bunch of potatoes at a time put them inside and use that to squeeze out all of the moisture that you can. Twist and squeeze the bag like it owes you money. 

3. Put salt on the shredded potatoes. Add one large egg and mixed thoroughly. You will need to add potato starch either that comes from your potatoes (the white layer at the bottom) or potato starch from a bag. The texture you're looking for is just enough so that it will hold together in the oil. 

4. Heat up your oil/cooking fat (my favorite to use is lard) and form a palm-sized piece of your potato mixture into a puck. You want it to be about the thickness of your pinky. Drop it in away from you. 

5. You want to fry until it's turning Amber in the center. You might get a couple burnt edges if yours are particularly crackly but that's a necessary sacrifice. Flip them a couple times to ensure even cooking. 


Serving Suggestions:

Besides the typical sour cream in the US I highly recommend Mexican or Honduran Crema. It's tangier and saltier than normal sour cream and it tastes significantly better for this application. You could also serve it with anything from ketchup to Japanese mayonnaise.