Peel potatoes and grate using a hand grater or food processor. Soak the grated potatoes in cold water. Squeeze as much liquid out as possible and transfer them to a second bowl.
In a heavy-based 8" skillet. Add the oil (about 1/8" deep) and heat. When it begins to ripple & quiver, take a fistful of potatoes, wring again and let fall loosely into the center of the pan, working quickly, cover the entire pan. With a fork, spread the potatoes to make a layer 1/2" thick. Cook the underside until it is a deep golden brown. Carefully flip the rosti in the pan or loosen it and put a dinner sized plate on top of the pan and flip the rosti onto the plate, then slide the inverted rosti back into the pan and continue cooking until the new bottom is browned, about 6-8 minutes.
Slide the rosti onto a cutting board. Cut into wedges or cut with a round pastry cutter for individual rosti. Serve with crème fraîche and your favorite caviar.
1 pound potatoes (Yukon Golds or Russets are best)
1 ½ teaspoon salt
3 tablespoom vegetable or olive oil
1 to 2 ounce of your favorite caviar