method
1. Preheat the oven to 200°C (400°F), Gas Mark 6.
2. Melt half the butter in a large frying pan and saute the onion and potato slices for 5-10 minutes, until golden and lightly softened. Transfer to a shallow gratin dish.
3. Place the remaining butter, flour. Milk, salt and pepper in a small pan over a low heat, whisking continuously until the sauce boils and thickens.
4. Pour the sauce over the potatoes and top with the grated cheese. Cover the dish with foil and bake for 50-60 minutes, until the potatoes are tender. Remove the foil and place the dish under a hot grill until the cheese is bubbling and golden.
serving amount
serves 4-6
rate this recipe
7.0
out of 10
3 users have helped to rate this recipe.
more information