We pulled up to the home of Tojikazu Kitamura, a bus driver who tends a half-acre family plot that has been handed down through the generations. Kitamura, a compact man in his 60s, came out of the house, handed the chef a bag of taro roots, and led us past a small stream to his farming plot. Suddenly, Nakahigashi broke away from us and rushed ankle-deep into the burbling stream. "You see these weeds?" he said, as he crouched over a clump of green and purple leaves sprouting along the embankment. "They're edible." He yanked out several bunches and washed the mud off the roots: wild watercress, upland cress, and water dropwort, he explained. Moments later, Nakahigashi strode over to a grassy mound at the edge of the field, dropped to his knees, and, using a small handheld scythe, cut away a knot of red leaves: wild sorrel. Then he probed the tangle of grasses further, searching for one-inch shoots of tsukushi, a bitter-tasting plant. On finding a shoot, the chef raised his eyebrows and smiled.