What type of butter is usually used for sautéing fish?

Clarified butter is the best choice for sautéing fish due to its higher smoke point compared to regular butter. When butter is clarified, the milk solids and water content are removed, leaving behind pure fat. This process allows it to withstand higher temperatures without burning, making it ideal for sautéing, where precise temperature control is important to achieve a nicely cooked fillet without an overly browned or burnt flavor.

Using normal butter may lead to the milk solids browning too quickly, resulting in a bitter taste and potentially a burnt appearance. Cooking spray can sometimes be useful in non-stick applications, but it doesn't provide the rich flavor that clarified butter can impart. Unsalted butter, while it can be used, still contains milk solids that can burn, making clarified butter a superior option in this particular cooking method.