Fondue gratin

Method

1. Preheat the oven to 170°C/fan150°C/gas 3½. Bring a large pan of water to the boil, then cook the potatoes for 6-7 minutes. Drain, then spread out on kitchen paper and leave to steam for a few minutes until cool enough to handle.
2. Meanwhile, melt the butter in a frying pan, add the onions and cook gently for 5 minutes. Add the garlic and cook for another 5 minutes until the garlic is fragrant and the onions are translucent but not coloured.
3. In a 2.5 litre gratin dish, scatter half the bread and half the potatoes in a layer, then top with half the onions and half the cheeses. Season well with salt and pepper and drizzle over half the cream and half the wine. Hold your thumb over the bottle of kirsch and sprinkle a little over everything. Repeat the layers with the rest of the bread and potatoes, onions and cheeses, cream and wine, and another splash of kirsch. There should be a good layer of cheese and cream at the top.
4. Transfer to the middle of the oven and bake for 1 hour or until golden, bubbling and crisp on top. Leave to stand for 5 minutes, then serve with cornichons, pickled onions, a bitter salad, if you like.