Preheat the oven to 375°F.
In a medium-sized mixing bowl, combine the pork and spice blend until the spices are evenly incorporated throughout the meat.
In a large skillet over medium heat, melt the butter. Place the onions, celery, and carrots in the pan and sauté until the onions and celery are translucent. Add the chestnuts and continue to cook for another 2 minutes.
Set the chestnut mixture aside to cool until you can touch it comfortably. Then combine the mixture with the meat and form into twenty-four 1 1/2-ounce meatballs.
Place the meatballs in a baking dish or on a rimmed baking sheet and bake for 30 minutes, or until cooked all the way through