My swiss friends lament that one the of the main problems making a rosti in the States is that we don't have the same potato over here. The best potato to duplicate, though, would be a yukon gold. We also use russets or whatever we have on hand, but results vary. Anyway, one boils the potato in the skin until it's done, or some cook to 2/3 done. The key is to let the potato rest overnight, or if in a hurry, 4 hours in the fridge. That firms it up. Then peel and grate, using a large coarse grate. In the non-stick fry pan, use oil mixed with butter, for best flavor. As it's cooking, don't disturb until a good crust has formed on the bottom, other than pushing the potatoes down to form 1 large flat potato pancake. Season with salt & pepper. Then I put a larger plate than the pan over the pan, and flip. The pancake should be on the plate at this point. Then you slide the pancake back in the pan with more oil, to get a crust on that side, too. It doesn't always work perfectly, and then you just sort of piece it together again. I also like mine pretty crispy throughout, so if it looks like the middle isn't crispy enough, I fiddle with it a bit to make sure it's crisped to my liking, and then I reform my pancake.
I usually serve this for breakfast or brunch in lieu of hashbrowns, but it also works will paired with a salad, sausage, or pork chops, or other meat, and maybe some green beans.
Sometimes I cheat and use the foil packaged precooked rosti. This is a swiss product that you can sometimes find in German markets. It's the next best thing, just be sure to season it, and use a spatter guard when you use this product, as it really spatters. Some brands are Hero, St. Galler, and Kadi.
ps.. another tip. Be sure to use a large fry pan, and don't use so many potatoes, that your pancake is too thick, or else you will have a problem getting the middle part crisped up. Pressing down on it also helps.
(Edited by Blue Heron at 10:23 am on Jan. 10, 2002)