I didn't expect meat-lover Eric to like this one, but he went back for seconds and thirds.
Polenta: 1 cup polenta mix, 3 cups water. Boil until thick.
Spread 1/2 polenta mixture onto prepared pie pan. Arrange mushrooms over it. Add pesto (I think I used about 2 tbsp). Spread the other half of mixture over it. Put a thin layer of cottage cheese on top. Add sliced tomatoes coated in olive oil to top. Bake 45 min at 350.
We didn't wait long enough for the pie to set properly after taking it out of the oven, but I think a good 20 minutes would be enough to make slices.