PS: Just to prove my point about eastern France and their cheese here's a map (from Wikipedia) of all ''official cheeses''
Recipe adapted from Inter France
500 ml fromage blanc or 250 ml ricotta cheese or cottage cheese (radical)
60 ml crème fraîche
1 egg + 1 for egg wash
100 g. coarsely grated Gruyère
Salt and pepper
333 ml. tepid water
Sea salt, for topping
500 g. puff pastry dough
1.Roll out the dough on a floured surface. Cut out rounds, each 12 cm in diameter. Transfer them to a baking sheet sprinkled with water. Prick them all over with a fork. Chill until firm, at least 15 minutes.Meanwhile, in a mixing bowl, beat together the fromage blanc or the ricotta cheese with the crème fraîche and 1 egg. Add 75 grams of Gruyère , salt and pepper.
2.Brush some egg wash on the edges of a chilled round. Place a walnut-size mound of the cheese mixture in the center of the pastry and pull up the edges of the round and pinch it into a triangular shape so the filling is completely enclosed. Repeat for the remaining dough rounds, arranging the corniottes on a baking sheet covered with parchment paper.Chill the corniottes on the baking sheets at least 30 minutes or until very firm or they will open during baking.
3.Heat the oven to 220°C.Brush the egg wash over the surface of the corniottes. Bake in the oven until lightly browned, about 15 minutes. Sprinkle each with 1/2 tablespoon of the remaining Gruyère and continue baking until the cheese melts and browns, 5 to 10 minutes longer.Serve as soon as possible.