In a mixing bowl, combine ground beef, pork, egg, breadcrumbs, milk, onion, garlic, spices, salt, pepper, and parsley. Mix until just combined.
Shape into small meatballs, about 1 inch each.
Melt butter in a large skillet over medium heat. Brown the meatballs in batches until golden on all sides. Transfer to a plate.
To make the cream sauce, melt butter in the same skillet, whisk in flour, and cook for 1–2 minutes.
Slowly add beef broth while whisking. Bring to a simmer.
Add heavy cream, Worcestershire sauce, and Dijon mustard. Stir until smooth.
Return meatballs to the skillet and simmer for 8–10 minutes until the sauce thickens and meatballs are cooked through.
Taste and adjust seasoning.