(Serves four to six)

3 large potatoes
2 medium sweet potatoes
1 small celeriac
30 g butter
2 cloves garlic, crushed
150 ml vegetable stock
150 ml cream
1 tbsp chopped parsley
Large pinch nutmeg
Salt and pepper
60 g grated Parmesan cheese

Peel the vegetables and slice them all about an eighth of an inch thick – I think that’s about three millimetres but it’s not critical. Put them in a pan of lightly salted water, bring to the boil and cook for two minutes. Tip them into a colander and cool quickly under cold running water, then drain well. Lightly butter a baking dish about 20 cm by 30 cm and spread the vegetables into it.

Preheat the oven to 190˚C. Melt the butter in a pan and fry the garlic for a minute or two without browning, then stir in the stock, cream, parsley, nutmeg and some salt and pepper. Bring to the boil, then pour the mixture over the vegetables.

Loosely cover the dish with foil, stand it on a baking tray and bake for 40 minutes. Remove the foil and sprinkle with the Parmesan and continue to bake for about 25 minutes, or until the vegetables are tender, brown and bubbling.

Let the dish stand for about 20 minutes, then cut into squares and serve.