MEAT MIXTURE: In a large bowl, combine the ground pork, grated yellow onion (See Note 1), minced garlic, panko, egg, heavy cream, nutmeg, allspice, pepper, and salt. Gently mix until just combined, being careful to not overwork the mixture.
FORM MEATBALLS: Use a 1-tablespoon measuring spoon to portion out the meat into balls. Lightly toss the meatball between the palms of your hand to form small, round balls. Place on a platter or baking sheet and repeat with the remaining mixture. Cover and refrigerate for 1 hour to help them hold their shape while cooking.
BROWN MEATBALLS: Preheat the oven to 375 degrees F and generously spray a 9x13-inch pan. Heat the canola oil (2 tablespoons at first) in a large cast iron or non-stick skillet over medium-high heat. Add half of the meatballs (making sure to not overcrowd the pan) and fry for 2 minutes. Flip and brown on the other side for another 2 minutes. Transfer to the prepared 9x13 pan and repeat with remaining meatballs. Bake for 17-25 minutes or until the meatballs are cooked through (160 degrees F.).
CREAM SAUCE: Meanwhile, prepare the sauce. Quickly wipe out the skillet used for the meatballs and melt the butter over medium heat. Once melted, whisk in the flour and cook for 1 minute. Gradually add in the beef stock and then vegetable stock, whisking constantly until smooth. Cook until thickened, about 2-3 minutes. Reduce the heat to low. Add in the heavy cream, soy sauce, and Dijon mustard. Simmer for another 1-2 minutes. Taste the sauce and add seasonings if needed (I typically add 1/4 teaspoon each of salt and pepper). The sauce is thick! If you'd like to thin it a bit, add additional stock slowly (1-2 tablespoons at a time) until the desired consistency is reached.
FINISHING: Toss cooked meatballs gently in the sauce. Serve over mashed potatoes or buttered noodles with a side of cranberry sauce or lingonberry preserves. Garnish with parsley if desired. Enjoy!