Here's the recipe I'm using (Nigel Slater's):
Tartafin
For 2, with the accompaniments below
450g waxy potatoes
2 cloves of garlic
2 tbsps olive oil
50g butter
100g semi-soft or easy-melting cheese, such as Gruyère, Port-Salut, Camembert, Taleggio or, for authenticity, Reblochon
I have been cooking potatoes in olive oil and then topping them with cheese for years. It is one of the simplest and most delicious suppers I can think of. I have used Italian Taleggio, French Cantal and Swiss Gruyère, and even goat's cheese on one occasion, to melt over the tender potatoes. What I did not know until recently is that it is a traditional French recipe, from Normandy. It was Thane Prince who put me straight, in her column in the Telegraph, when she published a version of this dish which she had found on a trip to Normandy, where they use Reblochon - a creamy local cheese.
Scrub the potatoes and slice them thinly, no thicker than pound coins. Peel and slice the garlic and cook it slowly, in a large sauté pan, in the olive oil and butter till fragrant and pale gold.
Lay the potatoes in the pan, cover with a lid and cook over a low heat for 20 minutes till you can push a sharp knife through the layers with little resistance. They should be quite soft and buttery.
Slice the cheese and lay on top of the potatoes. Cover and cook again for a couple of minutes till the cheese has just started to melt. Eat immediately. When served with sliced charcuterie, gherkins, olives and bread, this is one thing I would rather eat than almost anything else.