There were a gob of places on the Santiago Dock side of the town to eat veg fare. It was insane.. one place I remember was called Munchies, which is ALL vegetarian, and I think I ate there every day. Along the same little path there are four other restaurants that I can't recall the name of, but it's so small, you're not going to miss them.
Favorite Dish: drink the pineaple liquados at munchies. they're yummie.