The quatrième mur (‘fourth wall’) of a theatre is the invisible one that separates the actors from the audience. An apt name for this restaurant set in Bordeaux’ iconic Grand Théâtre. Philippe Etchebest plays a gloriously simple, understated score focusing on first-rate ingredients, high-flying technique, a side dish and a jus. The terrace on one of the opera house’s outdoor side galleries is heavenly. Bookings essential – two sittings at lunchtime and in the evening. The menus change weekly.