Gwen Stefani has been a rock star, an actress, a fashion designer and a coach on The Voice, and now she’s cooking up yet another job title: TV chef! “Gwen’s in talks to have her own cooking show on the Food Network,” a source exclusively tells Life & Style. “This is something she’s dreamed of for a long time.” Gwen, 48, has her friend Giada De Laurentiis, 47, the host of the Food Network’s Giada at Home, to thank for convincing her to take the leap. “Gwen has co-hosted with Giada before,” the source notes, “and had a real blast doing it.” When she starts her own show, the source says, Gwen likely will invite celebrity guests — starting with her man, Blake Shelton, 41. And if all goes well…