Bring a large pot of water to a boil with two teaspoons of salt.
Add the spinach and cook just until wilted, about 1 minute.
Drain the spinach in a strainer or colander.
Rinse with cold water until cool and squeeze the water out of each fistful of spinach.
Chop the spinach bundles into a ¾ inch width.
In a large skillet melt the butter with the garlic and onions.
Cook on medium low for 8-10 minutes or until the onions are translucent.
Add in the remaining kosher salt, black pepper and nutmeg.
Add in the flour and mix with a wooden spoon over low and cook for 2-3 minutes until the aroma is a bit nutty.
Add the half an half and cook until boiling.
Add in the mozarella cheese and cream cheese
Cook for 6-8 minutes or until the mixture has thickened.
Add in the spinach and the Parmesan cheese and stir to combine.
