Prep time: 90 minutes    Difficulty : 🙂     Servings: 8 1/2 pound fresh mushrooms, thinly sliced 2 tablespoons butter or margarine 4 eggs 1/2 pint dairy sour cream (1 cup) 1/2 pint small curd cottage cheese (1 cup) 1/2 cup grated Parmesan cheese 4 tablespoons flour 1 teaspoon onion powder 1/4 teaspoon salt 4…