Vegetarian food and China

Hi
Am going to Beijing.
Can anyone tell me how to ask for vegetarian food in China?
What is the phrase to ensure I get pure vegetarian food, and not food
prepared in meat stock, or food with pieces offish or poultry, or food
where the meat has simply been removed before serving?
If someone can also provide the chinese phrase in Chinese to explain
this (I understand that if one states one is buddhist and vegetarian
this concept is easier to explain) and even better provided ths chines
phrase in Chinese, I will print it out to show to restaurant people
when necessary.

Thank you very much for your help with this.

Cheers

Ganesh