Londoners who may have bought one of the River Café cookery books still return here regularly to be reminded of how it should be done, perhaps clutching a bottle of house-brand Tuscan olive oil as they leave. It's an experience you buy into, in every sense, reflecting the overwhelming success-story that Ruth Rogers and the late Rose Gray triggered when they opened in the unlikeliest of London locations way back in 1987. Finding the place still raises the odd harrumph of exasperation for first-timers, but perseverance pays off. On a summer day, the place is an especial joy, its small garden area looking over the Thames Path and the water. But inside is quite as bright and breezy, the white walls offset by an electric-blue carpet. An unwavering commitment to top-quality ingredients (some from Italy, much from here at home), treated with as little intervention as is consistent with the art of cooking, is still the name of the game. A brace of tenderly cooked Scottish scallops, their corals intact, are dressed in lentils, peas and mint for a first course that is stunning in its vibrancy. Flavours are no less alive in a fillet of sea bass, slashed and stuffed with herbs before being roasted in the wood-fired oven. Its accompaniment of whole roasted beetroot, Italian spinach and a variant of tapenade add well-gauged depth to the dish. Veal shin is simmered in no mere 'white wine', but specifically in Pieropan's benchmark Soave Classico, along with thyme and garlic, and teamed with zucchini, prosciutto and gremolata. The utter simplicity of the desserts, such as a slice of crisp-based almond tart topped with sweet, ripe strawberries, served with a cloudlet of whipped cream, makes you wonder why others resort to foams, jellies and meringues to make an impression. Well into its third decade, the River Café shows not the slightest sign of flagging.