Definitely give this recipe a chance -- it was excellent with these two minor changes: 1) Decrease the wine to 1/2 cup, and 2) add a tablespoon or so of tamari for a delicious, mellow, savoury flavour. The mushrooms add a lot of water in the cooking process, and the stew indeed is quite bland with the seasonings listed.
I was disappointed with this recipe. It tasted more like basil soup than it did Marsala. Next time, I would use half as much wine (unless your aim is to get drunk) and add more spices, as it tasted very bland. I would also add flour or tomato paste to help thicken up the "sauce"/broth.