Blame Paula Deen. Or heck, let’s leave her out of this for once. Blame generations of well-meaning chefs and cooks who have defined Southern cooking with adjectives like battered, fried, buttered, and smothered, rather than the most important one of all: fresh. Steven Satterfield, of Miller Union in Atlanta, isn’t the first chef to make the case that our diet is rooted in garden soil. But in his new cookbook, he presents a vegetable-centric cuisine that is as appealing in its restraint as a salt-and-peppered slice of tomato, particularly as we lift our heads from the larded stew pots of cold months past to nibble on new harvests of asparagus, peas, and strawberries. Root to Leaf is divided by season, and the spring chapter contains such uncomplicated creations as this spring onion pizza, made with a wholesome whole wheat dough.