This is a dish that appears not to have travelled far beyond Friuli and even there it's hardly commonplace. There are numerous ways of making it. Indeed the name is also attached to a dish of scalloped potatoes which bears no ressemblence to the excellent version served at the Hotel Franz in Gradisca d'Isonzo 40km north of Trieste. The balance of cheese and potato is crucial. The ordained cheese is Montasio - localism and all that. It is improbable that you'll find it in the UK. Saint Nectaire is the most reliable stand-in I've found but I guess Taleggio and Fontina would be ok.
500 g semi-hard cheese, coarsely grated
500 g potatoes, coarsely grated
2 or 3 banana shallots, finely chopped
Cook the shallots till soft in plenty of butter.
Add the potatoes and when they are getting soft add the cheese.
Cook for about 20 minutes over a low heat or in a bain marie.
The ingredients will eventually form a homogenous emulsion.
This can be fried in butter and olive oil - pour into a pan in which the mixture is about 3 centimetres thick. Cook for 10 minutes then turn into another pan to brown the other side. That will probably mean dropping it on the floor. Hence screams and flying knives which reveal the plagiarist's streak of culinary psychopathy.
Safer perhaps to separate the mixture into small discs which are not a problem to turn over.
Or pour the entire mixture into a gratin dish and cook in oven at a highish heat for 25 minutes, finish under the grill.
No matter which method is chosen the exterior should be fairly crisp. Do not let it burn.