Cheese sauces are creamy mixtures made primarily from melted cheese and a liquid base, often milk or cream. They are commonly used to enhance the flavor of various dishes, such as pasta, vegetables, and nachos. The most popular cheese sauce is cheddar cheese sauce, which is frequently used in macaroni and cheese. To prepare a basic cheese sauce, a roux is typically made by cooking flour and butter together, then gradually adding the liquid while stirring. Once the mixture thickens, shredded cheese is incorporated until melted and smooth. Variations can include additional ingredients like spices or mustard for extra flavor.