In Lebanese cuisine, the garlic sauce traditionally served with chicken shawarma is called toum.
Toum is a thick, white emulsion made primarily from garlic, neutral oil, lemon juice, and salt. Its name comes from the Arabic word for garlic. The ingredients are gradually blended so the garlic acts as an emulsifier, producing a texture similar to mayonnaise but without eggs.
Toum is especially associated with Lebanese grilled chicken, including shish taouk and shawarma. It is also served with grilled meats, potatoes, and bread. The sauce is intensely garlicky, and its flavor can mellow after resting.
Toum is sometimes confused with tarator, another Middle Eastern sauce based on tahini, lemon juice, and garlic. Unlike toum, tarator is sesame-based rather than an oil-and-garlic emulsion.