Rinse the octopus under cold water and place it in a large pot. Add chopped celery, lemon juice, bay leaf, peppercorns, and salt. Fill with water to cover the octopus, bring to a boil and simmer for 40-45 minutes until tender.

Once cooled, slice the octopus into bite-sized pieces.

In the same pot, poach the squid for 2 minutes until opaque, then remove. Poach the shrimp for another 2 minutes until pink.

In a mixing bowl, combine olive oil, lemon juice, tangerine juice, garlic, mustard, parsley, and salt to create the dressing.

In a large bowl, combine octopus, squid, and shrimp, then pour the dressing over the seafood and toss gently.