What is a knob of butter?

A knob of butter typically refers to a small amount of butter, usually around 1 tablespoon in size. It is commonly used in cooking and baking to add flavor and richness to dishes. Butter is a dairy product made from churning cream or milk, and it is mostly made up of butterfat combined with water and milk solids. It has a distinctive creamy taste and can be used in a variety of dishes, both sweet and savory. Butter is also a good source of vitamins A, D, E, and K, as well as healthy fats.