Put the egg yolk into a small bowl and whisk with a fork.
Dribble a little bit of Olive oil into the bowl with the yolk and whisk while doing so.
Repeat this over and over again until the mixture is thick, white and creamy. (you may need a little bit more/ less Olive oil.
When the yolk mixture is nice and creamy, add the mustard and mix again.
add the vinegar and parsley and mix again.
Chop the Cappers abit, or if you like the cappers whole put them in whole. (add as much or as little cappers as you like, but I usually add about 1 tablespoon), add abit of the capper juice as well to give the Sauce extra flavour (about 1 Teaspoon).
Add your spices, Salt and pepper and serve.
Note- This TarTar sauce keeps in the fridge for about 2 Days.