Hollandaise sauce is a rich, creamy sauce made from egg yolks, butter, and lemon juice or vinegar. It is one of the five mother sauces in classical French cuisine and is known for its smooth texture and buttery flavor. Typically, it is served warm and is a key ingredient in dishes like eggs Benedict. To prepare hollandaise, the egg yolks are whisked together with a small amount of water over gentle heat until they thicken. Then, melted butter is slowly added while whisking continuously to create an emulsion. This sauce is often seasoned with salt and a dash of cayenne pepper for added flavor.