Rösti is a Swiss-German dish, so technically neither. However as it is basically just pan-fried potatoes and therefore hard to screw up, any decent restaurant should be able to manage it
Thanks for the reply
In Gruyères opt for local and regional specialities - cheese of course with cheese fondue (so called "moitié-moitié mainly), then "double crème" with meringues and/or ice-cream, or "double crème" with berries - "myrtilles" (comparable to blueberries), strawberries, raspberries, blackberries.
Rosti - better "Röschti" as pronounced with a long "ö" - comes from one of the Alemannic dialects (also spoken in SW Germany, Baden mainly), and at least historically not necessarily made from potatoes, but bread with apples, pears, eggs.
And I wish the different ways making "röschti" were that easy - never managed to come close to what my grandmother made ..... . One of the reasons "röschti" is not easily available in restaurants is time required to prepare "röschti" with the right crispy crust.
Thank you swissdiver and jm2cents.
Yesterday was in old town and ate Rosti at "Café du Bourg-de-Four". It was tasty but didn't resemble pics I have seen earlier where the potatoes are thinly sliced and have lots of cheese . This has heated potatoes .
Unfortunately Rösti have largely gone the way of pizzas and often don't resemble the real thing. Basically Rösti contain potatoes (preferably cooked the previous day) and butter (and maybe a little salt and nutmeg for flavouring).
Lots of places don't use butter, because you need lots of it, the potatoes soak it up, and if prepared properly, it takes a long time to prepare. The recipe I use says you pan-fry the grated potatoes gently for 20 minutes (after having already cooked them the previous day). Not many restaurants are going to do that.
That is exactly what makes it delicious, the big amount of butter you add. I cook the potatoes at least two days ahead or if I cook potatoes in their peel for something else, I cook some more and plan a Rösti after two days. This avoids the potatoes being sticky.
There are however also areas where the Rösti traditionally is prepared with raw potatoes, but the amount of butter remains the same.Edited: 13 June 2018, 14:56
It is possible to have rösti with cheese but only as a variation of the basic, classic dish which is grated potatoes and as catmouse says a LOT of butter. Engadiner's point about cooking the spuds a day or more before and then grating them is essential. If you don't the potato all sticks together. It should come together to make the crust when cooking but not be what the British call "claggy".
Raw potato rösti is crisper than the cooked potato variety. Crunchy-er. (if that is a word!). To me they are very different and I make both...
Anyway Gruyères is not the place to find rösti. Fondue - yes. Especially the "moitié-moitié" That is wonderful - 50% Gruyere cheese and 50% Vacherin fribourgeois. (I would make a bet that jm2cents can make that perfectly!!)