A frozen, rectilinear, cuboidal block of closely controlled dimensions and weight, typically a nominal 7. 4 kg, usually made from white fish as an intermediate product for the production of fish fingers (fish sticks) and portions. It is composed entirely of skinless, boneless fillets (fillet block), that may be jumble-packed or orientated and layered, or composed of skinless, boneless fillets plus the recovered fish flesh from the V-cuts, for example, or composed entirely of recovered fish flesh (minced fish), termed a mince block or minced fish block. A proprietary polyphosphate mixture is often added to the fillets and/or mince before packing.