There's an old boys' network in the spice world ― behind the scenes and faceless, yet powerful. Turmeric is a major player. This rhizome, a ginger look-alike, gives a dark orange color to many everyday mixtures, like curry powders and some pickle relishes. In cautious Western cuisines, turmeric's individuality is usually masked; it rarely ventures on its own. But in Middle Eastern foods, the spice becomes a bold and visible presence. Faz Poursohi, who serves foods with Persian flair in his San Francisco Bay Area restaurants, uses turmeric to give an earthy intensity and golden sheen to normally passive chicken.