This is delicious at any time of the year but especially on those days when the bowl of grey sky is cupped close to the ground outside and trees stand bare and stark in a deep still silence. Inside, dry wood from the barn crackles and spits in the stove, the dog lies prostrate on the kitchen floor and the hum of chatter drifts in from the living room. Hot from the oven, sit this gratin in the middle of the table and dig in.
6 slices of bacon, chopped (optional)
420ml double cream
2 garlic cloves, sliced
1 tbsp fresh rosemary, finely chopped
1 red chili, deseeded and sliced
1 tbsp Dijon mustard
1 celeriac, peeled, quartered and thinly sliced
500g potatoes, peeled and very thinly sliced
Pinch salt / black pepper
1. Heat oven to 180C. Grill the bacon, if using, until cooked and lightly browned, then set aside.
2. Bring cream, milk, garlic, rosemary, chili and mustard to the boil in a medium saucepan, turn off and set aside.
3. Pour a little of the cream mixture onto the bottom of an ovenproof gratin dish. Arrange a layer of celeriac, scatter with bacon, then season. Pour over some more of the cream mixture and repeat the same process, alternating potato and celeriac, finishing with a layer of potato.
4. Cover with the remainder of cream mixture, then bake for 1-1¼ hrs, until golden and vegetables are tender when a knife is stuck in. Leave to sit for 5 minutes then serve.