looks lovely farfallina. I will make this tonight and use some mozzarella cheese. mum used to make rosti on the odd occasion but for some reason it was called "potato whitebait". the raw potato wasn't washed, but as it had to sit for about 10 minutes after grating a lot of moisture was just squeezed out. Instead of tomato and mushrooms, she just added onion. It will be nice to see what the difference is.