The most important discovery the conquistadors made when they arrived at the court of Moctezuma 500 years ago wasn't gold, silver, or precious stones; it was all the weird and wonderful stuff the Aztec king enjoyed for dinner. Most impressively there was mole, an elaborate concoction made almost entirely from ingredients never encountered in the Old World — chocolate, peppers, tomatoes, corn, a wide variety of nuts and seeds. Zazil, a casually upscale Westfield Centre dining spot specializing in dishes from Mexico's coastal regions, prepares the best mole negra in town. The mole Oaxaqueño is earthy, smooth, and smoky with a bare hint of sweetness and no individual flavor overwhelming another but each contributing to the depths and layers of the whole, the bitter chocolate sensed rather than tasted. You can experience it in a delectable grilled-prawn dish, as a sauce with the duck fritter appetizer, in the impressive seared salmon tower, or at lunchtime lending complexity and richness to a variety of enchiladas.