Stock is a flavorful, unseasoned liquid made by simmering bones, mirepoix (finely chopped vegetables), and boquegarni (aromatic herbs) in water. It is the foundation for many soups, sauces, and gravies. To make stock, bones and vegetables should be fresh and all fat and marrow removed before long, slow simmering. Stock should not be boiled or stirred vigorously, and scum should be removed periodically.