Add drained tuna, garbanzo beans, cherry tomatoes, avocado, black olives, cucumber and fresh parsley to a large bowl. Stir to combine. Add Greek yogurt, extra virgin olive oil and lemon juice to a small bowl. Whisk to combine.

Pour the yogurt sauce into the tuna mixture and stir to completely coat the ingredients. Season with salt and garlic pepper, taste and add more as needed. Garnish with fresh parsley and serve chilled.