Preheat the oven to 350 degrees and grease a small baking dish.
Add 3 tablespoons butter, garlic, and spinach to a large skillet and sauté until the spinach is wilted.
Remove from the heat and set aside.
Combine artichoke hearts, all but one green onion, and the remaining butter in a skillet and sauté for about 2–3 minutes. Set aside one green onion so you can use it as a garnish.
Add 1 cup mozzarella cheese, all parmesan cheese, cream cheese, sour cream, and pepper to taste. Stir together as the cheese melts.
If spinach is watery, use a strainer and drain the extra water out.
Combine the artichoke mixture and spinach, remove the skillet from heat, and place it into your baking dish. Sprinkle the remaining mozzarella cheese on top.
Place in the oven and allow to bake for about 20 minutes, or until the cheese is melted and starts turning a golden brown.
Garnish with the green onion you set aside and enjoy with your favorite Nut-Thins.