Prepare the Octopus: Clean the octopus thoroughly under cold running water. If not already done, remove the beak and eyes. In a large pot, bring enough water to cover the octopus to a boil. Add the bay leaf and black peppercorns.

Cook the Octopus: Add the octopus to the boiling water. Reduce the heat and simmer for about 45 minutes to 1 hour, or until the octopus is tender. You can check tenderness by piercing the thickest part of a tentacle with a knife; it should go in easily. Once cooked, remove the octopus from the water and let it cool slightly.

Form the Carpaccio: While the octopus is still warm, lay it out on a piece of plastic wrap. Shape the tentacles into a cylinder, ensuring it is tightly packed. Roll the octopus in the plastic wrap tightly into a log shape. Twist the ends of the plastic wrap to compress the octopus further, making a firm cylinder. Tie the ends to secure. Place the wrapped octopus in the refrigerator and chill for at least 4 hours, or overnight. This will help the octopus firm up and hold its shape.

Slice the Carpaccio: Once the octopus has chilled and set, remove it from the refrigerator. Unwrap the octopus and slice it as thinly as possible using a sharp knife or a meat slicer. Arrange the thin slices on a serving platter.

Slice the Carpaccio: Once the octopus has chilled and set, remove it from the refrigerator. Unwrap the octopus and slice it as thinly as possible using a sharp knife or a meat slicer. Arrange the thin slices on a serving platter.

Serve: Serve the octopus carpaccio immediately, either on its own or on a bed of mixed salad greens for a more substantial dish.