Preheat oven to 375°F. Clean dirt from mushrooms, remove stems and remove the black gills on the underside of the mushrooms. Place the mushrooms in a 9x13 inch pan in a single layer. Set aside. Put the dried fruit in a bowl and cover with hot water. Set aside. In a sauté pan over medium heat, brown the sausage until crumbled. Add onion, celery, zucchini and garlic and continue cooking another 3 to 5 minutes until the vegetables are soft but still have a bite to them. Remove from heat and transfer to a large bowl. Drain the water from the dried fruit and discard. Add the fruit to the sausage and vegetable mixture along with the egg, breadcrumbs and cheese. Season to taste with salt and pepper and mix thoroughly. Divide the mixture evenly between the mushrooms. Add 2 cups of water to the bottom of the pan, cover with foil and bake 20 minutes. Remove foil from pan and, if desired, sprinkle the top with more cheese and continue baking another 10 minutes. Remove from oven and serve.