It would be churlish not to use the mayonnaise I made to form the base of another sauce with it! Tartar sauce is not exactly complicated, the biggest thing is having things in the cupboard to knock it up, then balancing the flavours. Essentially, the capers provide the salt and the gherkins provide the sour. The shallot provides a bit of texture as well as a bit of tartness. The quantities are purely based on how you want it to taste and the texture/consistency you want. The only way to get it right is to try it. It probably wants to be kept on the sour side to complement the fish it is being served with. Egg is sometimes used but generally speaking, I would say that there is enough texture and flavour without needing to put it in, there is also the egg flavour from the yolk in the mayonnaise.
In terms of quantities, I would start with equal measures of everything and then add to taste.
The pickling juice from the gherkins makes an excellent thinner if you need it.
Makes as much as the amount of mayonnaise you use!
- Chop the ingredients that require it to the size you want for the texture, I tried to get things as fine as possible. If you want it really smooth you could put them in a food processor.
- Tip everything into the mayonnaise and stir.
- Check the flavour and see if you need to add anything to it.