Fillet is a culinary and butchery term that usually describes a boneless piece of meat or fish, but its exact meaning depends on the species and regional terminology. In fish preparation, a fillet is a side of flesh removed from the backbone. In meat terminology, it may describe a boneless cut or, in some markets, the tenderloin muscle.
A fish fillet is generally one side of the fish removed from the backbone. It may be supplied skin-on or skinless, pin-boned or not, and as a whole side or portioned piece. The filleting method depends on the species and body shape. A fish fillet should be checked for pin bones and trimmed to the required portion specification before cooking.
In British and French usage, “fillet” or filet can refer to beef tenderloin. North American menus more often use “tenderloin” for the whole muscle and “filet mignon” for a steak portion cut from it. The beef tenderloin is the psoas major muscle, located beneath the backbone. It is naturally tender because it performs relatively little work.
In other species, the word can refer to different boneless cuts. Pork fillet is the common British term for pork tenderloin, while chicken fillet commonly refers to a boneless breast portion.
Chicken fillet generally means a boneless breast portion. The small muscle beneath the breast is commonly called the chicken tenderloin, inner fillet or aiguillette. These terms may vary by supplier and market.
Fish fillets may be pan-seared, baked, poached, steamed or grilled depending on the species and thickness. Tender meat fillets may be grilled, roasted or pan-seared, while other boneless cuts require different cooking methods. Remove bones, silverskin or unwanted connective tissue as appropriate and use the correct cooking and food-safety controls for the species.
When ordering or writing a menu, specify the species, muscle or cut, skin status, bone status, portion size and trim standard. “Fillet” alone can be ambiguous between markets and may describe very different products.
Example: A fish fillet is portioned from the side of a salmon, while a beef fillet steak is cut from the tenderloin muscle.
Chef’s tip: Confirm the supplier’s cut specification before costing. A boneless fish fillet, beef tenderloin and chicken breast fillet have different yields, cooking characteristics and price points.
Related term: Tenderloin / Fillet explains the beef tenderloin cut in more detail.
Key distinction: Fillet is a broad term for a boneless cut or fish side. Tenderloin is a specific muscle, while filet mignon is a steak portion commonly cut from beef tenderloin.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
