Wimsey mentions that Bunter has prepared twaite meunière for his luncheon rather than the more traditional kippers. Meunière is a French culinary term which refers to both a sauce and a method of preparation, primarily for fish. The word itself means "miller's wife". Thus to cook something à la meunière was to cook it by first dredging it in flour. A meunière sauce is a simple preparation-brown butter, chopped parsley, and lemon, and the name refers to its unelaborate rustic nature. The fish is likely trout ("truite" in French, but is misspelled as "twaite" in the subtitles.)