- 750g potatoes, unpeeled and finely sliced (use a mandolin if you have one)
- 1 red onion, sliced into rounds using a mandolin
- For the sauce:
- 600ml milk
- 1 onion, halved
- 3 bay leaves
- Handful black peppercorns
- 50g butter
- 50g plain flour
- You will need:
- A gratin dish, buttered
- Start by making the sauce. Gently heat the milk in a pan with the onion, bay and peppercorns. Set aside, covered, to infuse for 1 hour. Strain.
- Melt the butter in a pan, stir in the flour and cook for a few mins on a low heat. Slowly whisk in the milk until smooth and thickened.
- Heat the oven to 220°C. Tightly arrange a layer of potatoes on the base of the gratin dish, top with a layer of sauce, then top with red onion and season well.
- Repeat the layering process, finishing with a final layer of potatoes topped with sauce.
- Cover with foil and bake for 30 mins, then reduce the heat to 180°C. Remove the foil, and bake for another 45 mins until golden brown.
This article originated on www.womanandhome.com
You can cook this the day before and reheat in the microwave or covered in a low oven until heated through.