Thanks to his work at Fruition and the love heaped on him by local and national press, Alex Seidel was already a household name — at least among food-lovers — when Mercantile Dining & Provision opened in Union Station last September. Lonne Cunningham, his pastry chef, was not. But that's about to change, as more and more people are exposed to Cunningham's work. With a pedigree that includes stages at Gramercy Tavern and Le Bernardin in New York and a pastry mindset influenced by years as a cook, he plays with flavors like a veteran, finishing crème caramel with pistachio cakes, candied kumquats and pistachio dust, for example, or adding a hint of cardamom to a chocolate pot de crème. Cunningham's plated desserts are only available at dinner, but you don't have to wait until then to indulge: Mercantile's market is open all day, so there's always a good time to stop in for a chocolate croissant or an Oreo-like LCO cookie.