Gruyère is a firm, dense, hard cow's-milk cheese from the Swiss Alps, the archetypal Alpine mountain cheese: pale gold, smooth and close-textured, with a deep nutty, savoury, fruity-earthy flavour that grows more complex with age. It is one of the world's great melting and cooking cheeses — the heart of fondue, the bubbling crown of French onion soup, and the filling of a croque-monsieur — and a superb table cheese in its own right.