This is the most famous Greek appetizer, due to its simplicity and great taste! It is basically yogurt with garlic and cucumber. It complements most of the Greek lunches / dinners especially with meat or just appetizers. The ingredients are: Greek yogurt (it has to be 'stragisto' or thick texture Greek yogurt), cucumber, olive oil, garlic. It has to be cold when served, otherwise its not good. Can be complemented with olives. Its secret is on the yogurt, it has to be the special Greek yogurt Stragisto with the thick texture, otherwise it doesn't work! Tzatziki is one of the basic ingredients of the famous Souvlaki sandwich.