In large stock pot boil octopus until tender (1 hour 45 minutes to 2 hours). Take out and let cool. When cool, clean and slice. In a large mixing bowl, add celery, juice from the lemons, olives, garlic, onion, parsley, and sprinkle with olive oil. Mix well and season salad with salt and pepper. Remove from mixing bowl and serve at room temperature.
Recipe courtesy of Bobby Flay