There are those among us who grow vegetables on the roof, only eat beef from cows that once frolicked contentedly on New York State pastures, and haven’t bought a banana since the last century. And where do they go for dinner? Roman’s (243 DeKalb Ave., nr. Vanderbilt Ave., Ft. Greene; 718-622-5300), for one, the Italian-accented sibling of Williamsburg’s pioneering Diner and Marlow & Sons. The menu changes constantly, a policy that infuriates creatures of habit but that the Underground Gourmet finds refreshing, especially when it brings such surprises as the season’s first sweet Maine shrimp, or a flurry of fava beans, whipped into a purée or adorning a bowl of spaghetti ($12). Card-carrying locavores also find sustenance at Northern Spy Food Co. (511 E. 12th St., nr. Ave. A; 212-228-5100), a cozy East Village nook that celebrates local products in unexpected dishes like upstate-freekeh risotto enriched with mascarpone ($12). At Brooklyn Heights’s Iris Cafe (20 Columbia Pl., nr. Joralemon St.; 718-722-7395), the coffee is Stumptown, the turkey salad is made from antibiotic-free gobblers lovingly raised on Pennsylvania’s Koch’s Farm, and the caramel sticky buns are baked in-house. And then, on opposite ends of the culinary spectrum: Eat (124 Meserole Ave., nr. Leonard St., Greenpoint; 718-389-8083), where the overindulged U.G. goes to detox on farm-fresh fare like carrot-turnip-spelt salad and rhubarb tonic, and Bark Hot Dogs (474 Bergen St., nr. Flatbush Ave., Park Slope; 718-789-1939), Brooklyn’s preeminent source for Slow Food fast food, from lard-basted, Rochester-made boutique franks to New Jersey–strawberry milk shakes.