Over high heat place a pot with water and bring to boiling.
Add the octopus in the pot, cover it lid and let it boil for about 5-8 minutes. Make sure it is almost covered in liquid.
Then reduce the temperature to a medium-low and continue to cook for about 45 minutes until tender.
Turn off the heat leave it aside and add balsamic vinegar, wine, and oregano you can leave it overnight to marinate.
Allow the octopus to steep until the liquid has cooled or even better, place in the fridge overnight.
Next day place it to a bowl and add balsamic vinegar, dried Greek oregano, olive oil, and season with ground black pepper and sea salt.
Grill the octopus to your barbecue on a high heat for about 2-3 minutes on both sides.
Place the grilled octopus to a plate and squeeze fresh lemon juice, and drizzle with extra-virgin olive oil.