Quick: Where can you eat vegan doughnuts for breakfast, vegetarian Chinese for lunch, and 13-bean soup for an afternoon snack? Hint: In the same city, you can feast on sustainable fish for dinner, prepared by one of the country's celebrity chefs, and Kind Apple Cobbler for dessert -- the "raw" version. New York? Maybe. Seattle? Probably. Las Vegas? Definitely. Surprised? The locals aren't. Green? You bet your life. All-night buffets and free cocktails are Vegas' usual claim to culinary fame, but their notoriety has overshadowed long-established, healthier outposts: a pick-your-own orchard, a natural-foods store, a vegan doughnut shop. Now a …