Peel potatoes and coarsely grate using the large hole side of a box grater or a rosti blade in a mandolin.

Melt 2 Tbsps butter in an 8-10" non-stick skillet over medium low heat. Add the grated potatoes. Spread them evenly around the skillet. The depth should not exceed 1-2 inches.

Allow potatoes to cook undisturbed about 3 minutes. Press them down with a spatula after the 3 minutes. Cover the skillet and allow them to cook undisturbed about 10 minutes. Remove cover and let them cook another 5 minutes.

Using a inverted plate over the skillet, flip the potato pancake onto the plate. Melt remaining butter in the skillet. Slide the pancake back into the skillet. Repeat above, allowing potatoes to cook undisturbed 3 minutes, cover and continue cooking about 10 minutes, remove cover and cook another 5 minutes.

Season with salt to taste. Cut into quarters and serve.