Peel potatoes and shred or grate on a box grater to get 4 cups. If you don't have a box grater, cut your potatoes in to small cubes.
Place potatoes into a bowl and cover with cold water. Swirl them around and drain. Repeat 4 times, or until water runs clear.
Transfer to a clean dish towel or paper towels and squeeze to drain out any extra water. Open the towel and spread out the potatoes to dry while you heat the butter.
In a heavy skillet, add the butter over low heat and gently melt. Once melted, turn off the heat and use a spoon to skim off the white milk solids floating on top. You won't get it all, but do the best you can.
Turn the heat up to medium high and heat 2 minutes. Add potatoes and spread them evenly and reduce the heat to medium. Leave the potatoes undisturbed and cook 8 to 10 minutes until the potatoes are golden brown (you can peek if needed) and they release easily from the skillet.
Flip in one piece or in sections and cook an additional 5 to 8 minutes until golden brown on the other side. Sprinkle with salt to taste and serve warm.