Separate the head and tentacles from the body of the squid. Cut the tentacles free from the head and discard the head and rinse the tentacles. Skin the squid bodies, remove the quill and thoroughly rinse inside and out and cut into ringlets. Steam the squid for 2 to 3 minutes or until tender. Place in a large mixing bowl and cool.
In a medium skillet heat one tablespoon of olive oil and garlic over medium heat and sauté for one minute or until garlic is fragrant and soft. Add the celery and lemon juice and bring to the boil. Lower heat and cover. Simmer celery until just soft. Remove from heat and cool.
Combine the cooked squid, celery, chickpeas, olives, parsley and remaining 1/2 cup olive oil. Season with salt and freshly ground pepper. Can be refrigerated overnight. Bring to room temperature for 20-30 minutes before serving.