Stir-Fried Chicken with Celeriac and Mushrooms

Whilst celeriac is a favourite addition to casseroles and makes a traditional slow-cooked braised vegetable to serve with game or roast beef it also lends itself well to a simple stir-fry. The flavour given to the rest of the ingredients is that of celery, but the texture is quite different. It is important to slice it thinly for quick cooking.