Golden onions and potatoes au gratin with rosemary

Ingredients for 4 people
  • 1 kg potatoes
  • 4 golden yellow onions
  • 500 ml milk
  • 100 g butter
  • rosemary
  • salt and pepper
  • Wash the potatoes, peel and cut into very thin slices.
  • Clean the onions and slice them into very thin rings.
  • Arrange the potatoes and onions in alternating layers in a well-buttered baking dish, add salt and pepper to each layer and sprinkle with small knobs of butter and rosemary leaves.
  • Press the flan down with your hands and cover it with milk.
  • Bake in a preheated oven at 180°C until the milk has reduced and the golden, au gratin surface crust has formed.