That's a person specialized on cooking only vegetables, although that person isn't necessarily a vegetarian. He may be cooking for vegetarians and that person may be not one of them. I could call him "Veggie's cooker"
Don't call someone
vegetarians or veagans if your hardcore no milk stuff like that
I'd call them a pathological truther.
superficial
Gothic
solo
Rhino
Liberal
Only if you are an embezzler.
A monolingual.
An altruist
The only reason is if you want to get them to leaf.