Garum was a popular fermented fish sauce used in ancient Roman cuisine. Made from the intestines of fish, it was mixed with salt and left to ferment in the sun. The resulting liquid was prized for its strong flavor and was used to enhance various dishes. This condiment was similar to modern-day fish sauce and was often used in cooking or as a seasoning. Garum was widely traded across the Roman Empire, and its production became a significant industry. Different regions produced their own variations, leading to a range of flavors and qualities.