Add the juice of 1 lemon and the halved celery rib to a large pot of water and bring to a boil. Add the shrimp and squid and return to a boil; cook for 2 minutes. Discard the celery. Drain the seafood and let cool in a bowl set inside a larger bowl of ice.
In a bowl, whisk together the olive oil, garlic, basil and parsley. Add salt and black pepper to taste. In a large bowl, combine the chopped celery, tomatoes, juice of 3 lemons and the crushed red pepper. Add the cooled seafood and the dressing and toss to coat; marinate for 1 hour. Serve over the greens.
