Cooking the octopus
Fill a large pot with water until half full. Place over high heat, and bring to a boil. Using metal thongs, dip the octopus into the boiling water for 5 seconds, then lift it and repeat the process 3 times. Then, dip the octopus into the boiling water, add the bay leaves, peppercorns, onion, and lemon wedges. Cover with a lid and simmer for 45 - 60 minutes, depending on the size of the octopus. The octopus is cooked when you can effortlessly push the forks into the meat.
When the octopus is cooked, let it cool completely by leaving it in a pot filled with cooking water for at least 2 hours or overnight. Then, using metal thongs, transfer the octopus to a large bowl. Peel the octopus and cut it into smaller slices, and place in a large bowl.
Cut the olives in half. Finely dice the onion, garlic, and chili. Chop the parsley, and add all the ingredients to the octopus in a bowl. Make the dressing. In a small bowl, combine the olive oil, lemon juice, lemon zest. Season with salt and pepper. Pour the dressing over the octopus, stir to combine, and serve.