This pizza works with just about any vegetable that is wearing out its welcome in your fridge or windowsill. The idea is to make a thick sauce from caramelized vegetables and onions with tomato paste, and to use no cheese save parmesan or pecorino. We happened to have a few green peppers, some cherry tomatoes and a bit of kale. Caramelized peppers are mushy and sweet, not too different from fire roasted peppers (but less work, I say). They melt in the mouth, and are a nice sweet balance to the acidity of tomatoes.
Makes a 12 inch pizza with a very thin crust — good for 1-2 people.