Fontina is a semi-soft, washed-rind cow's-milk cheese from the Aosta Valley high in the Italian Alps, sold as a flat round wheel with a thin reddish-brown rind and a pale straw-yellow, supple, elastic interior dotted with a few small eyes. It is mild yet richly flavoured — buttery and creamy young, growing nutty, earthy and faintly woodsy with age — and it is one of the great melting cheeses, the indispensable base of the Piedmontese fonduta.