Combine pork, garlic powder, pepper, salt, allspice, nutmeg & 1/2 tablespoon of mustard in a medium bowl. Mix until very thoroughly combined – using your hands works best for this. Roll into 1-tablespoon balls. (about 20)
Heat the butter & olive oil in a large, non-stick frying pan over medium heat. Add the meatballs & cook, turning the balls, for 5 to 8 minutes until they’re browned all over. Remove from the pan to a plate.
Add the onion (& a little extra oil if necessary) to the same pan. Cook, stirring occasionally, for 5 minutes, or until softened. Add the garlic & cook for 1 minute or until fragrant. Add the remaining mustard & stir to combine.
Add the broth & cream & whisk to combine. Bring to the boil then cook, stirring occasionally, until the sauce starts to thicken. Add the sour cream & stir to combine. Add the meatballs. Cook for about 5 minutes or until hot & cooked through. Remove the heat & add chopped parsley. Stir until well combined. Season with salt & pepper to taste. Serve with toothpicks. And extra parsley leaves.