Step 1

Peel the celeriac, then cut it into very thin strips; you can use a food processor or julienne cutter, or cut it into 1.mm-thin slices, stack these on top of each other and cut into batons of a similar thickness. As you work, periodically squeeze the lemon juice on top of the cut celeriac, to stop it discolouring.

Step 2

Rinse the celeriac in cold water and place in a bowl.

Step 3

Add whole grain mustard

Step 4

Add Sherry vinegar and leave for 20 min

Step 5

Add olive oil mayonnaise and season to taste.

Step 6

Finely cut chives or spring onions and add to the remoulade.

Step 7

Place egg yolk, lemon juice, vinegar, mustard, salt and pepper in a food processor. Blend until combined (for about 30 seconds).

Step 8

With the food processor running, pour olive oil into the mixture in a very thin (and slow-moving) stream. Continue to blend until it has thickened. If your mayonnaise is too thick, add a little water to thin it out.

Step 9

If using a blender add all ingredients and 2 tablespoons of cold water.