Paul Virant puts a spin on the classic summer side dish by tossing warm potatoes with a mustardy vinaigrette and handfuls of arugula. "I grow a lot of arugula in my garden," he says. "It's so easy to grow, it's a joke. A farmer once said to me that if everyone who had enough space planted a garden, we could produce enough food to feed the entire country. I don't know how that would work, but it's fun to think about."