The best chefs turn to two shops for superlative seasonings. New York City's La Boite a Epice (laboiteny.com) creates spice blends used by Lyon's Chris Leahy and Le Bernardin's Eric Ripert, whose favorite is the Salvador, a mix of pimenton, saffron, and seafood essence. San Francisco's Le Sanctuaire (le-sanctuaire.com) is stocked with berries, barks, peppers, and pods. Comme Ca's David Myers and Thomas Keller's pastry chef, Courtney Schmidig, are regulars. The French Laundry uses the store's Tahitian vanilla beans to flavor desserts and the saffron-and-vanilla sauce it serves with butter-poached lobster.