Make the sauce: melt the butter in a large skillet over medium heat and saute the garlic for 30 seconds. Sprinkle in the flour and cook for 1 minute or until bubbly and golden. Whisk in the milk and simmer until thickened about 1 minute. Stir in the spinach, artichoke hearts, cream cheese, Parmesan cheese, ⅔ cup shredded mozzarella, oregano, basil, red pepper flakes, salt, and pepper, and cook until the cheese has melted about 2-3 minutes.