Please suggest anywhere on public transportation or walking in the city.
veg naturals is vegan, in Malden, just accross from oak grove station (orange line).
in beverly (via beverly depot stop on the commuter rail - rockport and newburyport lines), you can try the organic garden cafe. all raw menu with organic beer and wine, too.
most places will do a vegetarian dish upon a request (if you don't like what they already offer -- i cannot recall the last time i was someplace that didn't offer at least one) and there are a gajillion middle eastern and indian places whose menus are 50% if not more vegetarian. french and Italian places also do well with veg. i was a vegetarian for years and never had a problem dining out.
there is also grezzo, which is 100% raw, on prince st., but that is pretty spendy.
are you hankering for something special cuz your op is pretty vague.
Not vegetarian or marketing itself as "healthy", but Henrietta's Table uses tons of fresh, varied (and local) produce, especially at lunch time. I had lunch there last week and was pleasantly surprised to find 4 or 5 interesting salads on the menu. (I had the arugula, nectarine, goat's cheese, spiced pecan salad special.) There are always a couple of vegetarian cooked entrees too. That's where I go when I want a broad, tempting selection of vegetables, without any mystery ingredients. It's nice to find that minus an atmosphere of deprivation.