This disk-shaped semisoft cheese from the Extremadura region is produced largely from the milk of merino sheep. Following an ancient practice, a local thistle is used in place of rennet to coagulate the unpasteurized milk, giving Torta del Casar its exotic, floral-herbal bitterness. As the cheese matures and ripens, it becomes spectacularly oozy and sensuous, with a terrific complexity. Traditionally, Torta is warmed in the oven ever so slightly, the top rind is cut off, and the insides are scooped out with a spoon. This is my favorite cheese in the world, expensive but worth every cent. A similar, but somewhat less stunning, cheese from Extremadura is la Serena.