© David Loftus
Preheat your oven to 200°C/400°F/gas 6. Place the potatoes, celeriac and onion in an earthenware-type baking dish. Season generously. Add the garlic, ¾ of the cheese, the cream and the parsley stalks. With a spoon, move everything around to mix all the flavours. Sprinkle over the extra cheese, and bake in the preheated oven for 50 minutes, or until tender and golden. Sprinkle over the parsley leaves. I like to leave the gratin in the dish, pop it in the middle of the table and tuck in!
• 1kg potatoes, peeled and sliced into 1cm slices