To make the mayonnaise, place all the ingredients, except the oil, into a food processor and blend until pale and creamy.
With the motor running, pour in enough oil, in a steady stream, until the mayonnaise is thick.
For the Remoulade, place the celeriac, lemon juice, mustard, seasoning and parsley into a large bowl.
Mix together well and stir in the home-made mayonnaise. Season to taste.
Mix to combine and serve.
Type the ingredients you want to use, then click Go. For better results you can use quotation marks around phrases (e.g. "chicken breast"). Alternatively you can search by chef, programme, cuisine, diet, or dish (e.g. Lasagne).