Add ½ pound ground pork, ½ pound ground beef, ¼ cup panko bread crumbs, 1 tablespoon chopped fresh parsley, ¼ teaspoon ground allspice, ¼ teaspoon ground nutmeg, ¼ cup minced onion, ½ teaspoon garlic powder, ⅛ teaspoon ground black pepper, ½ teaspoon salt, and 1 large egg to a large bowl. Mix until fully combined.
Form 20 meatballs with the meat mixture. Heat a large skillet over medium heat and add 1 tablespoon olive oil and 1 tablespoon unsalted butter. Add the meatballs to the heated skillet and cook for 10-15 minutes, turning them continuously until they are browned on all sides and cooked through to an internal temperature of 165 degrees Fahrenheit.
Remove the meatballs from the skillet to a plate and cover with foil to keep warm.
Sauce
Add 4 tablespoons unsalted butter to the skillet and melt over medium heat. Whisk in 3 tablespoons all-purpose flour and cook until the mixture bubbles and browns.
Slowly whisk in 2 cups beef broth and 1 cup heavy whipping cream. Add 1 tablespoon Worcestershire sauce and 1 teaspoon dijon mustard. Simmer the sauce for about 5 minutes, until it starts to thicken. Season with salt and ground black pepper to taste.
Add the meatballs back to the skillet and simmer in the sauce over low heat.
While the meatballs simmer in the sauce, bring a large pot of salted water to a rolling boil. Cook 16 ounces uncooked pasta to preferred doneness according to the directions on the package and strain.
Add the pasta to the meatballs and sauce and toss to coat. Serve immediately.