Preheat the oven 325°F.
In a large bowl, combine the ground beef, ground pork, egg, tomato sauce, onion, tamari sauce, mustard, garlic, salt, pepper, and liquid smoke. Mix until well combined.
Shape into 1½-inch meatballs and place on a rimmed baking sheet. Bake the meatballs for 45 to 60 minutes, until cooked through and browned.
Meanwhile, make the sauce: Place the butter in a saucepan and heat until the butter sizzles and brown flecks appear, stirring constantly to keep the butter from burning. Reduce the heat to low. Stir in the cream cheese, broth, Parmesan, and nutmeg. Simmer for at least 15 minutes. The flavors
open up if you simmer longer.
When the meatballs are done, remove them from the oven, place them on a serving tray, and serve with the sauce.