Serves 4 This is my favourite way to use celeriac and is an ideal side with cold ham, salamis or tongue. When I want to keep this vegan, or when I don’t have an egg in the house, I just go with a mustard dressing ( see recipe for Waldorf salad, below) and find it works just as well. Ingredients 1 medium celeriac Lemon juice 1 egg yolk 1 tbsp plain Dijon mustard 175ml olive oil Salt and pepper Dijon mustard to taste 1. First, bring a pot of water to the boil and add a few drops of lemon juice to it. 2. Peel and cut the celeriac into long thin matchsticks either by hand, through a food processor, or by using a mandolin to slice very thinly then cutting into strips with a sharp knife. 3. Add the celeriac, along with a big pinch of salt to the boiling water very briefly – 20 seconds at the most. Drain and rinse under cold running water. 4. Next make the mayonnaise in a liquidiser by mixing the egg yolks, mustard and a squeeze of lemon juice, then slowly drizzle in the oil, a few drops at a time at first, then continue by adding the oil in a steady stream until fully used. Add salt and pepper, taste and adjust seasoning if needed, adding more mustard to suit your taste. 5. Mix the celeriac with the mustard mayonnaise very well, making sure it’s coated evenly.