Houston's Spinach/Artichoke Dip

2 pkgs. frozen chopped spinach
1 1/2 cans of artichoke hearts, chopped and drained
1 chopped onion
1 stick butter
1/2 tsp. cayenne pepper
salt and pepper to taste
8 oz. cream cheese
8 oz. shredded monterey jack cheese
4 oz. shredded swiss cheese
4 oz. shredded mozzarella cheese
4-6 oz. heavy whipping cream
4 oz. fresh parmesan cheese

Cook spinach, drain and set aside. Saute onion in butter until tender. Beat cream on medium speed and gradually add the cream cheese until it forms a creamy mixture. Mix all the ingredients together except for the parmesan cheese. Let chill for at least 2 hours. When ready to serve, top the mixture with parmesan cheese and microwave for 5 minutes, stir and serve with tortilla chips, crackers or gourmet breads.