Tenderize the octopus by gently pounding it on a clean kitchen surface.

Repeat this process at least 10 times.

In a large pot, bring 12 cups of water to a boil over high heat.

Briefly dunk the octopus into the boiling water for a few seconds, remove, and repeat this process two more times, leaving the octopus out of the water for a minute between dunkings.

Transfer the octopus to a platter.

Add the bay leaf, onion, peppercorns, parsley, and salt to the pot.

Bring the water to a boil again over high heat if necessary.

Return the octopus to the pot, reduce the heat to low, cover, and simmer until tender, approximately 1 hour, depending on the size of the octopus.

Drain, discard the bay leaf, and let the octopus cool.

Scrape off any loose skin and cut the body and tentacles into bite-size pieces using scissors.

In a small bowl, whisk together the olive oil, red wine vinegar, chopped onion, chopped garlic, chopped parsley, salt, and black pepper.

Add the octopus pieces and mix to coat.

Cover the bowl and let the octopus marinate in the refrigerator overnight.

Serve the Mediterranean Octopus Salad cold or at room temperature.

Enjoy this flavorful Andalusian-style dish!