The following excerpt is from “A White House Chef Who Wears Two Hats,” published this week in the New York Times. It offers a profile of the Obama family’s personal chef, Sam Kass, who serves up policy advice along with his own style of local, organic cooking. Read how a 29-year-old with a history degree and looks that earned him a slot on People magazine’s 100 Most Beautiful People list is now one of the most influential advocates for a better, more sustainable food system.