One of the essential minerals and oldest seasonings has gone gourmet. Forget about the white, fine-grain, mass-produced salt crystals of the past. Chunky sea salts in hues of beige, pink, red and black have taken over kitchens, tabletops and gourmet grocery aisles around the globe. Prized by chefs, connoisseurs and home cooks, they come from France and the Mediterranean coast, from salt pans in Tunisia and Majorca and from countless other sites, including Hawaii, Australia and Bali. In the Mediterranean sea salt is produced by an age-old technique. Here sea water is collected in shallow basins and allowed to evaporate in the sun. As it dries up, salt forms at the base of the pans. There it takes on the color of the clay or other natural materials found on the bottom. The salt at the top remains pure white. In France this delicate salt is known as fleur de sel. Light tasting and quick dissolving, it’s primarily used to finish dishes but it occasionally appears in baked goods. What do cooks do with all …