Chiang Mai is one of the city in South East Asian that love Vegetarian. As my experience, many Vegetarian resto around, with lot's of menu, fresh, free MSG and good price. Over 40 vegetarian-only restaurants plus many more vegetarian-friendly options.
Okay , I put "Chiang Mai" after India, the place that must be visited by vegetarian traveller.
I know, it's very frustrating, if you are traveller and vegetarian. When you are hungry and want to eat, you must explain what you want to eat to the locals people, who are not familiar with the word vegetarian, sometime with sign language if they not speak english.
But if you are in Thailand you just have to remember one word , "Jay", mean you are Vegetarian and need Vegetarian food :)
The first place i tried was "Taste from Heaven" just 100 meter away from my hotel. I pick curry soup, fried morning glory, fried tofu and cold lemon grass tea. The taste is good.Enough to make my stomach happy.
This place also offers cooking classes and some of social projects to save the elephants. Interesting!
Here more : http://www.taste4heaven.com/
Okay, im finish with my lunch. Now... many other restaurant waiting to be tried.
Note : Here some of vegetarian Resto that recomended to try : Pun Pun, Cafe Compassion, Free Bird Cafe, Khun Churn, Tianzi Tea House, May Kaidee's, Gap's House and Giva Raw Food.