Not vegan, not vegetarian, and not cheap (unless you buy used): Vegetables from Amaranth to Zucchini
, by Elizabeth Schneider, is, I think, the definitive vegetable cookbook.
It has forking everything, with extensive discussions about each vegetable, what the pros do with it, and several recipes for each. Some recipes are accidentally vegan, and many are easily veganizable with obvious 1:1 substitutes of butter, milk, or broth; a few with eggs would be trickier. But you are going to see ingredients lists with the words "beef broth" in them, if that type of thing grosses you out.
Amazon doesn't have a preview, but Google books does, except for blocking the photos.