The tartare sauce is delicious with cold fish or seafood.
Cut the pickles and capers finely. Peel the spring onion and chop it finely.
Then chop up the tarragon, parsley and chervil.
In a bowl, mix the mayonnaise, hard-boiled egg yolk, Bourgogne mustard, pickles, capers, tarragon, parsley, chervil and Cevennes onion