Skillet Fish Italiano
["1 small onion, sliced", "2 Tbsp. margarine or butter", "1 lb. fish fillets, fresh or frozen, thawed", "1/4 c. lemon juice", "1/2 tsp. oregano leaves", "2 c. sliced zucchini", "1 c. sliced fresh mushrooms (about 4 oz.)", "1/2 c. chopped tomato", "1/2 c. (2 oz.) shredded Swiss cheese"]
["In large skillet, cook onion in margarine until tender.", "Add fish, lemon juice, oregano, zucchini and mushrooms; cover and simmer 10 minutes.", "Top with tomato and cheese; cover and simmer 2 minutes or until cheese melts.", "Serve immediately.", "Serves 4."]
["onion", "margarine", "fish", "lemon juice", "oregano", "zucchini", "mushrooms", "tomato", "Swiss cheese"]