1. To make the hummus, combine the chickpeas, tuna, eggs, tahini, lemon juice, parsley, garlic, cumin, pepper and chickpea juices in the work bowl of a food processor. Add sea salt if desired. Cover and process until smooth, stopping to scrape down the sides with a spatula. Add additional water as needed to blend. Taste and adjust the seasonings. Divide into 4 containers with lids, garnish with paprika, cover and refigerate.
2. Divide the vegetables among 4 containers with lids. Place each pita bread half in a small plastic or wax paper bag. Cover and chill.
3. At lunch, spoon the hummus over the lettuce, tomato, and cucumbers. Stuff a portion of this mixture in a pitz half and eat the rest on the side with the celery sticks.
4. SUBSTITUTION: Replace pita bread with 1 orange and 1 small apple.