What to do with celeriac Buying Choose a celeriac root that feels heavy for its size, with no discoloured parts. Store in the fridge, in the salad drawer. If you don't use all of it at once, wrap the remainder tightly in clingfilm and return to the fridge. Preparation Cut away all the skin, revealing the creamy white marbled flesh. Dispose of any brown parts or interwoven roots at the base. It is usual to discard at least a quarter, so allow for this when buying. It discolours quickly, so after chopping and until use immerse in a bowl of water with a splash of lemon juice or white wine vinegar. Eating Celeriac is very versatile. Boil for 20 minutes then mash it or mix 50/50 with other mashed vegetables -- potato, carrots, swede or turnip. Add to pured soups for a lovely rich texture. It also makes a tasty gratin. Slice and slow bake with stock for 45 minutes, top with a dusting of grated cheese. Or cut into large chips and roast in a little olive oil (40 minutes). In France it's served in remoulade sauce as a salad dish served with cold meats and fish.