Celeriac & walnut gratin

1 large celeriac
2 tbsp walnut oil
300ml vegetable stock
handful chopped walnuts
100g blue cheese (or any tasty cheese)

Heat oven to 190C. Peel, quarter and very thinly slice the celeriac. Toss in the walnut oil, salt and pepper, and spread over a gratin dish. Pour over the stock and bake for 40-45 mins, then sprinkle with the walnuts, crumble over the cheese, then cook for 15 mins until crisp and golden.

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