Simple tartare sauce

Method

1. Place the egg yolk in the small bowl of a food processor with the mustard powder, half the lemon juice and some seasoning.
2. Pulse to mix, then add the oil really slowly, drop by drop at first, until the mixture begins to emulsify and you have a lovely thick mayonnaise.
3. Add the remaining lemon juice and taste to see if it needs more seasoning.
4. Scrape into a bowl and stir through the chopped capers, gherkins, parsley and shallot. Taste again and add more of any of the flavourings if you need to.