roughly tablespoon-sized portion of butter. It is  not an exact measurement, and the amount can vary  

depending on the context or individual preference.  Typically, a knob of butter is a small piece that  

is cut or broken off from a larger block or stick  of butter. This term is commonly used in cooking  

and recipes when an approximate amount of butter  is needed, often for sautéing, frying, or adding a  

bit of richness and flavor to a dish. When using  a knob of butter, it is generally understood  

that precision is not critical, and the actual  amount can be adjusted based on personal taste.