Chamkar is my fav resto in Siem Reap. There is not much pure vegetarian resto around this small town. While some place have western vegetarian menu, here they serve authentic Khmer food menu. It taste so good for asia tongue like me.
The location is not easy to find. Hide inside small alley of Pub Street. Cozy place inside old small building style. Try to come around lunch time because after 6 pm this place is always full of vegetarian traveller.
My fav one is the "Cambodian Wedding Day Dip" and green curry with special vegetable that just grow in cambodia "amok" with nice cambodian brown rice. I eat this menu everday with local cambodia black coffee.
The problem here is the staff not talking good english and so quiet. You need to try to be friendly and they will try hard to help and understand your language.
But still this is the best place to sit and relax around siem reap.
Price : 10 $ - 15 $