1. Scrub the celery root thoroughly in cold water to remove all traces of dirt

2. Place a pan of salted water on the heat and let it boil

3. Put the unpeeled celery in the boiling water and let it cook for about 40minutes or until the celery is tender

4. Leave it to cool slightly

5. Peel the celery root and finely chop it

6. Puree the celery through a sieve

7. Blend the puree with the mashed potatoes

8. Add the butter and the cream to the potato mixture

9. Season to taste with salt and pepper

10. Just before serving, heat the puree over low heat

List of ingredients required:

1 lb celery root/ celeriac
3 tablespoons double cream
1 and 1/2 oz butter
Salt and black pepper
3/4 lb cooked mashed potatoes