Celeriac and truffle mash

Truffle has become a rather expensive treat as the production of the tubers is dwindling – because there are fewer oak and hazelnut trees and less favourable soil conditions – and the world-wide demand by wealthy gastronomes is rising exponentially.
In the 1925 book of Tante Marie, for traditional family cooking, you can find recipes that call for “several truffles of a good size” to be cooked in wine to accompany poultry. A truffle of 100 grammes (Tuber Mélanosporum at the Lalbenque market) costs 110 euro nowadays so they are not really used any more as a side dish.
But they are just a subterranean mushroom with a subtle smell and an earthly taste.
Instead of using it as a delicate, and expensive, addition to a fine piece of poultry or venison, I like truffle most when it is used in a rather straightforward way in a risotto or an omelette.
In the Grand Véfour restaurant in Paris (chef Guy Martin), I once tasted a “hachis Parmentier” – an oven dish of potatoes and minced meat – with truffle and that was divine.
In the following recipe, I am combining celeriac – the root of celery – potatoes and truffle in a sort of “fruits of the ground” winter dish.

Truffles are in season from December to February and celeriac from October to March. Potatoes are harvested in September to November and then available from storage. I could have used fresh black truffle, but I opted for a cheaper alternative of truffle peelings in a small glass jar.
Celeriac is little-known as a root vegetable but it has a delicate taste and is full of vitamins, minerals and fibres. It can be used raw or cooked. Some people are allergic to celery.

Ingredients

• One celeriac (I had 1.3 kilo)
• 400 grammes of potatoes
• 12.5 grammes of truffle peelings
• One litre of stock (beef, chicken or vegetable)
• One table spoon of cream
• Lemon juice

Steps

1. Peel the celery root, then cut into cubes.
2. Cook for 30 minutes in a pan filled with the stock and water. Add some lemon juice to keep the celery from turning dark.
3. Peel the potatoes and cut in parts, add to the celery for 20 minutes.
4. Take the celery and potatoes from the pan. Keep the cooking liquid.
5. Mash the potato and celery, add cream and any cooking liquid to obtain a smooth, but not runny, mash.
6. Incorporate the truffle peelings.