Preparation:

The octopus must be kept in ice for at least 24 hours to cook faster. If you bought a fresh octopus, first clean it and then freeze it. Remove the eyes; pierce the skin with a knife on the side of the eye, then pull the knife under the eye and take it out – make sure it doesn't spray you. Pull out the teeth with your fingers; turn the lower part upside down and clean the entrails. Wash and freeze. Ice will soften it. Octopus shrinks a lot during cooking, so it should be put in slightly larger quantities, especially if it is made without potatoes.

Cook the octopus without defrosting it in a pot with cold water, just to cover it. It will be cooked the fastest in an express pot with a little water, and if you cook it in an ordinary pot, you will speed up the cooking if you put 2-3 corks in the water. The cork pulls the scale out of the water, so the octopus is cooked sooner. In some recipes (not for salad) the octopus is served whole. Then defrost it and take it by the body, then slowly lower the tentacles into the boiling water – they will curl nicely. Repeat 2-3 times then and put in the entire octopus. The octopus is cooked when the fork gently passes through the meat. Cool it in the water in which it was cooked.

Take the cooled octopus out of the water, and separate its tentacles from the body. Peel off all the skin, it's easy – grab a tentacle by one end, squeeze and pull the skin towards the other end. (To one’s preference, the skin can be left on). There are small, thin, plastic "bones" in the body of the octopus, so clean them too (it's no big deal if they remain because they are soft). Slice the octopus in smaller pieces, not too small, slice the tentacles to e.g. 2 cm in length. Put it in a bowl.

Vegetables:

Cut onions, regular or purple, into tiny cubes. A perfect alternative for onions are spring onions. Chop parsley into tiny pieces. Cut tomatoes into cubes, cherry tomatoes are even better because you can simply cut them in halves. Wash and drain the capers from the vinegar. If you make a dish with potatoes, cool the potatoes that are boiled in skin, peel them and cut into small cubes. Salad with potatoes should not be left. That's why I specially cut potatoes for the salad into small cubes (season with: onions, salt, pepper, olive oil and homemade vinegar or balsamic vinegar) and serve them with the octopus. Wash the arugula salad and drain it well.

In the bowl with the octopus, add the prepared vegetables: onions, tomatoes, capers, parsley, potatoes if you use them, arugula (you can mix it into the salad or put it as a base for the salad – explanation at the bottom of the recipe), then season with: salt, pepper, fine olive oil, vinegar (preferably balsamic vinegar or lemon juice).