I first cut the head of octopus off and wash it nicely. (There's a slippery layer on octopus but it goes away when boiled) If you enjoy the taste of the head, you can also boil it to not waste it. Just be sure that you've cleaned it very carefully. Octopus is boiled in a pressure cooker (depends on the size) for 20-30 minutes. After placing the octopus in the cooker, I add two soup spoons of cumin and water that is equal to two or three fingers' height and cook it in the medium heat. After taking the pressure cooker of the heater, I open the cover and let the air out. Later, I clean the octopus nicely. When I cook it like that, it's easier to clean. The skin comes off very easily (to understand if it's cleaned, you must check the legs to see if they're smooth and white.) Then, I slice the legs of the octopus like a dice and add green onion and gherkin pickle. Lastly, I add the olive oil and lemon. You don't need to add salt because the salt of octopus is enough. Before serving the salad, you must add olive oil and lemon few hours earlier. Because octopus really absorbs the olive oil and the lemon. Enjoy!