The sauce on this pizza is actually an eggplant puree. I roasted cubes of eggplant with some olive oil, salt and pepper at 425 for about 30 minutes. I pureed the eggplant with some olive oil and balsamic vinegar - you can add a little water to thin it out if you need to. I spread the eggplant puree on pizza dough and topped it with feta, roasted red and yellow peppers and olives. I baked it at 450 on a pizza stone for about 15 minutes. After it came out of the oven, I finished it off with some sliced green onions.
I pressed my eggplant puree through a sieve to remove the seeds before I put it on the pizza dough. It's optional, but it makes for a better consistency.