In a large pan, on high heat add butter, reduce to medium heat add garlic, onions, Spinach cook until all the moisture is then reduced.
In a large bowl, add sautéed spinach, salt, black pepper, and cream cheese a scoop at a time, and mix well.
In a cast iron pan on medium heat add Spinach mix, sour cream, half and half cream, mozzarella cheese and spread evenly on top, then add parmesan cheese.
Place in oven at 350 degrees, for 30 minutes, until cooked. Remove from oven and let cool and ready to serve.