I made this casserole this weekend with some extra zucchini I had on hand. With a few alterations, it was a hit. The kids actually asked for seconds when I thought the zucchini would turn them off.
I used an entire box of whole wheat penne pasta, olive oil, no mushrooms, 2 zucchini instead of 1 and frozen chopped spinach thawed and drained. Oh most importantly, 8oz of cream cheese, extra flour and some milk along with the chicken broth to make it creamer. I still can't believe the whole family came back for more.