Tzatziki, tzaziki, or tsatsiki (τζατζίκι) is a Greek meze or appetizer, possibly of Turkish origin, also used as a sauce for souvlaki and gyros. Tzatziki is made of strained yoghurt — in Greece and Turkey usually sheep's-milk or goat's-milk yoghurt — to which are added cucumbers (either pureed and strained or seeded and finely diced), garlic, salt, cracked black pepper and usually olive oil, dill, sometimes lime juice and parsley, or mint. Olive oil, olives, and herbs are often used as garnishes as well.