If you can, place the octopus in the freezer for 3 to 4 hours to break down its fibers. Then take it out and place it in cold water to thaw.
Boil a large pot of water. When the water boils, add salt and put in the octopus. Cover and let it cook gently with a bay leaf between 40 minutes and an hour. It depends on the weight of the octopus. The more it cooks, the more tender it becomes. Some people prefer it al dente, however!
At the end of cooking, check with a sharp knife if it is tender enough. Then turn it off and let it cool in its water.
Once cooled, drain it and refrigerate it a few hours or until the next day.
Take it out of the refrigerator half an hour before cooking that it is not too cold. Cut it up and grill it in a frying pan or on the plank with a little olive oil, some fleur de sel and lots of ground pepper!