I arrived at Sustain, a two-month-old Miami restaurant, clutching my favorite dinner date: low expectations. After all, Sustain’s chef, Alejandro Pinero, works almost exclusively with ingredients produced within a 50-mile radius. A 50-mile radius of Miami? Sounds like a punch line, even to someone who has written about South Florida agriculture. But the low expectations didn’t last long. Pinero trained under Michelle Bernstein (of Michy’s) and worked at Casa Tua, the haute Italian pit stop in Miami Beach, and he hasn’t let his ideals cloud his judgment about what it takes to make a restaurant soar. The menu is filled with wonders like the “50 Mile Salad” ($9) of wood-oven-roasted beets, pickled red onions, caramelized carrots, mixed brassica greens from Paradise Farms (in nearby Homestead) and soft crumbles of fromage blanc from Hani’s Mediterranean Organics (based in Miami). Another standout was the pumpkin swordfish crudo ($13). The fish (caught locally and named for its pinkish flesh), in a bath of citrus liquor, is the midway point between sashimi and ceviche. Corn bisque — vegan and, at $6, a bargain — was luscious. The strip steak ($28) with marrow gravy made for a terrific main. The cut on the menu changes from night to night so that the restaurant can make full use of the cows it purchases from 4 Arrows Ranch, in Ocala. “We’ll go into every part of the animal,” said the managing partner Jonathan Lazar, who added that the cows “never see antibiotics, never see a feed lot, never see growth hormone; they roam 800 acres on a farm, eating wheat grass and wild berries.” True, Ocala is more than 50 miles from Miami, but “we visited dozens of farms and this is the best one we found.” Lazar and his partner, Brian Goldberg, were determined to give Miami something new without, he said, “trying to be too hippie-ish. We don’t want to come off as educators, or preachers — that would be the worst thing. We just wanted to support local farmers and get off the industrial-agricultural grid.” They are willing to sacrifice revenue to virtue: it’s one of the few restaurants in America that won’t serve bottled water. (There are, however, lots of bottles. The restaurant’s well-stocked bar includes, if you must know, biodynamic wines and small-batch liquors.) Even the décor consists mostly of recycled items, including the salvaged cypress that was used for the tabletops. But the one thing that isn’t recycled is the menu, which is drawing foodies to Midtown Miami (a new mixed-use development near the Design District), some of them from much farther away than even those Ocala cows.