If you have access to vegan cheese, hummus, and leafy greens, sandwiches are always a easy option. Also, if you are able to, there are brands of organic, vegetarian soups that come in containers that you don't need to refrigerate until they are opened, so you can buy them and open them as you need them, and eat them plain or use them in other dishes.
Also, anything that involves throwing a bunch of beans, guacamole, cheese, etc together can't be ruined too badly.