Common Roots executive director Carol McQuillen strives to impart many lessons: Eat organic foods, increase everyone's access to them and take good care of the soil. But the lesson on which intern Ziheng Wang is focusing at the moment is decidedly more basic.

The 22-year-old University of Vermont senior slips a round pizza peel under the flatbread baking inches away from the ashy logs in Common Roots' outdoor clay oven at Wheeler Nature Park in South Burlington. He rotates the pie a few degrees, then a few degrees more. His first job, he explains: Make sure it doesn't stick.