500 gm celeriac, cut into julienne
120 gm good-quality mayonnaise
Juice of 1 lemon, or to taste
2 tbsp each thinly sliced mint and flat-leaf parsley
2 small green chillies, finely chopped
2 tsp wholegrain mustard

Combine ingredients in a bowl, season to taste and stand for 30 minutes for flavours to develop.