I know, it seems like sacrilege in the land of offal, but I'm traveling with two friends who are devout vegan. No animal products - no meat or dairy. Alas, no gelati. They are also real foodies with very sophisticated palates. Obviously, any restaurant will prepare a pasta pomodoro or primavera. And there's always pizza bianco and fried artichokes. But does anyone know of a truly great vegan restaurant in the city?