Begin by rinsing the cleaned octopus under cold water. In a large pot, combine the octopus with the quartered celery, halved lemon, bay leaves, peppercorns, and salt. Bring to a gentle boil, then dip the tentacles in the water to curl them. Lower the heat and let it simmer for 40–45 minutes, until the octopus is tender.

Once the octopus is fully cooked, carefully remove it from the pot and place it on a cutting board to cool slightly for about 10 minutes. Slice the octopus into bite-sized pieces.

In a separate pot filled with salted water, bring it to a boil. Add the squid rings first, cooking them for about 2 minutes until opaque, then add the peeled and deveined shrimp, poaching for another 2 minutes until pink and curled. Drain and set aside.

In a jar, combine the freshly juiced tangerines, juice from one lemon, olive oil, minced garlic, and honey Dijon mustard. Seal and shake until well emulsified. Adjust seasoning as desired.

In a large mixing bowl, combine the cooled octopus, squid, and shrimp. Pour the dressing over and toss delicately to coat. Adjust seasoning with salt and chopped parsley.

Serve the seafood salad at room temperature or refrigerate for up to 12 hours before serving for enhanced flavor.