Should one find oneself in a parlor conversation about dining history, one could validly submit that the Rex Whistler, opened in 1927 within the Tate Britain, began the trend of fine dining inside great museum institutions. Back then it was a bit of a lark, encircled by Whistler’s whimsical mural The Expedition in Pursuit of Rare Meats, in which a food-finding expedition travels on bicycle through lands populated by unicorns and truffle dogs, but in years since, the restaurant has garnered serious appreciation for its rich wine list—the sommelier will even consult with you before you arrive. Today's luncheon menu champions British seasonal produce, from Scottish salmon to Yorkshire mutton to succulent guinea fowl.