Cut a 3-foot-long piece of heavy-duty aluminum foil; fold in half lengthwise and set aside. Toss together all the ingredients in a bowl to make the marinade. Transfer the green bean mixture to the aluminum foil sheet, arranging in a mound in the center. Carefully fold one end of the aluminum foil over the other and pinch the sides to close, creating a neat pouch.
Preheat a grill to medium-hot. Place the aluminum foil pouch directly on the grate and grill for about 10 minutes. Carefully open the pouch slightly to peek inside and check if the green beans are cooked through and sizzling (be careful of escaping steam). Transfer the foil pouch to a plate and unwrap it. Serve the green beans directly from the pouch.
Photograph by Todd Coleman (c) 2011
Reprinted with permission from The Japanese Grill: From Classic Yakitori to Steak, Seafood, and Vegetables by Tadashi Ono & Harris Salat, copyright (c) 2011. Published by Ten Speed Press, a division of Random House, Inc.