Sounds like Tartiflette, which is French:
serves 6
750g potatoes, peeled
1 onion, peeled and sliced very thinly
150g lean smoked back bacon, snipped
150ml dry white wine
4 tablespoons creme fraiche
150g taleggio cheese
freshly ground black pepper
Cut potatoes in half and boil until just tender but still a little firm. drain and cool.
fry onions in oil for 10 mins until very tender. add bacon and fry for further 3 mins.
heat oven to 190c, gas mark 5. Cut potatoes into thin slices and place in a 2 litre baking dish.
pour the wine into the pan of onions and bacon and bring to the boil, then pour it over the potatoes.
drizzle over the creme fraiche
take the rind off the cheese, cut it into thin slices and arrange over the top. season with black pepper.
bake for 20-25 minutes until tender and golden brown.