Try the Unplugged Kitchen for simple vegetable recipes, and some unique ones too. I love that book.
And Farmer's Wife's Guide to Vegetables and Fruits- SUPER simple veggie/fruit recipes- the fruit one is mostly desserts, IIRC, but nice fruit based ones. I haven't read the books in years, but I still want them.
And The Vegetarian Mother's Cookbook has some simple vegetarian recipes that can be veganized as well.