In a large bowl, combine ground beef, ground pork, kosher salt, black pepper, diced onion, minced garlic, and chopped parsley. Stir until just combined.
In a medium bowl, mix together bread crumbs, whole milk, and egg until fully incorporated.
Add the milk mixture to the meat mixture. Using your hands, gently mix everything together until just combined. Do not overwork the meat.
Roll the meat mixture into 1-inch balls and set aside on a plate or tray.
In a large Dutch oven over medium heat, melt the butter. Once melted, add the meatballs in a single layer, working in batches if necessary to avoid overcrowding.
Cook the meatballs, turning occasionally to brown all sides, for 10-12 minutes or until fully cooked through. Transfer the cooked meatballs to a plate and cover loosely with foil to keep warm.
Reduce the heat to low. In the same Dutch oven, add the warm sour cream, flour, Worcestershire sauce, kosher salt, and black pepper. Stir constantly, scraping up any browned bits from the bottom of the pot, until the mixture is heated through and smooth.
Increase the heat to medium. Slowly pour in the beef broth while whisking, making sure there are no lumps. Bring the mixture to a boil.
Once boiling, add the uncooked egg noodles. Cover the pot, reduce heat to low, and simmer for 7-8 minutes, stirring occasionally, until the noodles are tender.
Return the cooked meatballs to the pot and stir gently to combine and heat through.
Serve hot, garnished with chopped fresh parsley. A dollop of sour cream on top is optional but delicious.