Transport yourself to the sunny Mediterranean with this flavorful veggie sandwich. Start with a crusty baguette or ciabatta and spread some creamy tzatziki sauce on one side. Layer on sliced cucumbers, tomatoes, red onions, and Kalamata olives for a burst of Mediterranean flavors. Add some crumbled feta cheese and fresh basil leaves for an extra kick. This sandwich is perfect for a picnic or a quick and easy lunch. The combination of fresh vegetables, tangy sauce, and salty feta cheese will leave you craving for more.