Think of the Loire Valley and images of idyllic chateaux and picturesque countryside spring to mind. RSJ could not be further from this, a restaurant with a slightly grubby exterior tucked away on a side street near Waterloo. However, the main event here is the wines. The Loire constitutes one of the most impressive but most undervalued wine regions in France, a long way metaphorically and geographically from its more fashionable Bordeaux and Burgundy-based siblings. Nonetheless, the Loire, stretching from Nantes on the Atlantic Coast to just west of Paris offers everything in wine terms, from sparkling to sweet via dry and in all hues, white, rosé and red. No other wine region in France can quite match this and no other restaurant I have visited in either the UK or France can quite match RSJ’s range of some 250+ Loire varieties. It gets better than that. Many are available at RSJ in both half-bottle and single-glass format, priced competitively from £4 a glass and £12 a half-bottle. Unsurprisingly, staff (whom, one gets the impression, had been long-serving at the restaurant) were both knowledgeable and enthusiastic. Although we clearly came for the food too, there was no attempt made to rush us through our meal and indeed we were encouraged to stay once we had finished dining to sample more wines. We worked our way back and forth along the Loire Valley, beginning with a bone-dry, lip-tingling Muscadet and finishing with a remarkably structured Bourgeuil. The food was relatively basic, but well-executed and at £17 for two courses can neither be faulted nor seen as expensive. My onglet steaks for the main were perfectly tender, horseradish dumplings wonderfully innovative and the sauce (a parsley jus) a welcome complement. One of my dining comrades also singled out for praise her starter of devilled chicken livers, toasted brioche, fried duck egg and smoked bacon. A cholesterol-heavy combination, but beautifully presented and, again, with pitch-perfect meat. A definite hidden gem of a restaurant. Come first for the wine, but also for the food.