Tuna and Vegetable Salad

Ingredients

• 8 stalks of celery from the center, including the leafy tops, finely chopped
• 6 ripe plum tomatoes, finely chopped
• 1 can (15 ounces) chickpeas, drained
• 1 medium-sized onion, finely chopped
• A handful of coarsely chopped flat-leaf parsley leaves
• 1/2 cup coarsely chopped pitted black olives
• 2 cans (6 ounces each) Italian tuna, drained
• 2 lemons
• 1/3 cup olive oil
• Salt
• freshly ground black pepper