My wife and I were in Canton for one night and we tried Bombay Sitar. The Vegan options there were more than the average restaurant, and our server was very friendly and knowledgable. She went through the menu telling us what was vegan, and she knew to have the chefs not cook with ghee.
My wife at the Aloo Gobi and I had the Bhindi Masala. Both were excellent, and went very well with the Roti bread we had on the side. This isn't an amazing restaurant, but it's very good, affordable, and friendly. If you're looking for something vegan in Canton, I would definitely recommend Bombay Sitar.
Cons: Dry dishes (but we were told by server)