Zucchini Delight

INGREDIENTS

• 1 (10 3/4 ounce) can condensed tomato soup, undiluted
• 1 tablespoon lemon juice
• 1 teaspoon sugar
• 2 garlic cloves, minced
• 1/2 teaspoon salt
• 6 cups zucchini, sliced 1/2-inch thick
• 1 cup onion, thinly sliced
• 1 cup bell pepper, coarsely chopped
• 1 cup mushroom, sliced
• 2 tablespoons parmesan cheese, grated