Mint Used in Asian Restaurants

Would like to know which mint variety is used in Asian restaurant cooking.

There are hundreds of different mints grown and used around the world. Often there are slight regional or national differences in the cultivars grown, or there are bigger differences in the species grown.
In Vietnamese green grocers in Toronto, we have seen what we call "vietnamese mint", a type of Mentha x gracilis. We have also seen a type of spearmint called "improved spearmint". Both of these are available from Richters. Thai green grocers are selling much the same.
Other major Asian cuisines such as the Indian and Chinese cuisines generally do not feature much use of fresh mint. The Japanese cuisine also does not use much of the true mints (Mentha spp.) but it does feature prominently other members of the mint family such as perilla.