Preheat oven to 400°F. Grease a 9x13-inch baking pan and set aside.
Over medium-high heat, melt 1 tablespoon of the butter in a sauté pan. Add in the chicken and cook until cooked through and no longer pink, about 7-10 minutes.
Remove from the pan and set aside. Add in the zucchini and cook until just tender. Stir in the garlic, thyme, salt, pepper, and nutmeg. Cook for 60 seconds or until fragrant. Remove from the pan and set aside.
2 zucchini, 3 cloves garlic, 2 teaspoons fresh thyme leaves, ½ teaspoon kosher salt, ½ teaspoon ground black pepper, ¼ teaspoon ground nutmeg
Melt the remaining 1 tablespoon butter. Whisk in the flour, cooking for 60 seconds. Slowly whisk in the chicken broth and then the milk. Simmer for 5 minutes to thicken.
⅓ cup all-purpose flour, 1 cup low sodium chicken broth, 1 cup whole milk
Stir in the cream cheese and 1 cup of the mozzarella until melted.