Cut the onion in to tiny cubes or grate it. Put salt on the grated onion and leave it for 10-15 minutes.
Put the ingredients in a bowl and mix them well with a fork. Put the salted onion in the mixture.
These amounts are approximate. I like "kÃ¶rÃ¶zÃ¶tt" if it's spreadable but someone like it a bit harder. You'd put garlic in if you like.