• Bring a stockpot of water to a boil. Scrub and rinse potatoes, do not peel, and add to boiling water.

  Parboil the potatoes for 12-15 minutes. Drain well and allow to cool to room temperature. You can also refrigerate for several hours or overnight.
  
• When potatoes have cooled, shred potatoes into thick shreds and set aside.
  
• In an 8" non-stick skillet, heat 2 tablespoons of butter between medium and medium low until butter is melted. Add shredded potatoes and press down evenly until flat. Use the spatula to press in the sides of the potatoes until it becomes even and disc-shaped.

  Cook for 12 minutes or until the bottom of the potatoes are crispy and golden brown.
  
• Remove from the heat and place a plate over the top of the skillet so you can flip it over onto the plate, cooked side up. Don't try to use a spatula to flip it. It will fall apart.
  
• Melt the remaining butter in the skillet and then slide the potatoes back into the skillet, uncooked side down.
  
• Cook for an additional 12 minutes or until crispy and golden brown on the bottom. Remove from skillet and serve.
  

My favorite variation:

• Set oven to broil.

  Place Rösti on an oven-safe skillet or baking sheet. Add cheese (I use shredded gruyere), sliced tomatoes, 2 slices of prosciutto, and more cheese over the top. Broil for 2 minutes or until cheese melts. Top with sunny-side up egg.