A tomato sauce is any of a very large number of sauces made primarily out of tomatoes, usually to be served as part of a dish (rather than as a condiment). Tomato sauces are common for meat and vegetables, but they are perhaps best known as sauces for pasta dishes. Tomatoes have a rich flavour, low liquid content, very soft flesh which breaks down easily, and the right composition to thicken up into a sauce when they are cooked (without the need of thickeners like roux). All of these qualities make them ideal for simple and appealing sauces.