Really, you can use whatever vegetables (and amounts) you want. I love corn, so I usually go overboard. I'd guess I throw in a couple cups of corn and a cup of green beans.
Throw everything in a large skillet and bring to a boil. Cover and simmer for 15-20 minutes. That's it!
The original recipe (not vegan) says to sprinkle the top with cheese. Feel free to use vegan cheese, but I add a dollop of vegan sour cream and mix it up a bit.
I've made this for my husband and some friends. All of them are meat eaters, and all of them loved it.