Greg Fellman opened the local Seven Cups, a franchise based in Tucson, with a mission. After living in China, where his interest in tea blossomed, he hoped to introduce Denverites to the subtleties of fine Chinese teas by sharing his knowledge while offering an exclusive selection of quality, organically grown leaves. And he does it there every day, selling dozens of loose-leaf varieties and an inexpensive tea service. But on Friday afternoons at 3 p.m., Fellman hosts a weekly tasting where the sampling is free and the ambience, enhanced by Chinese artwork and rosewood furniture, is lovely.