In a large bowl combine ground beef and pork; mix with your fingers, breaking up any lumps. Mix in all the other meatball ingredients (except the olive oil) until combined.
Using a cookie scoop or your hands, shape the mixture into 1 ½-inch balls. (Place on a clean platter, cover and refrigerate for about 30 minutes, if possible - this helps them retain their round shape when cooking.)
In a large nonstick skillet, warm the olive oil over medium-high heat until shimmering. Working in batches to avoid crowding, add the meatballs and cook turning continuously until browned on all sides and cooked through, about 5-6 minutes. Repeat with the remaining meatballs. Transfer to a plate and cover with foil.
Add the butter to the skillet and once melted, whisk in the flour; stir to combine and cook stirring constantly for about 1 minute until no lumps remain and flour just begins to brown.
Slowly whisk in the beef broth and then the heavy cream. Whisk in the soy sauce and mustard; bring to a simmer, then turn down the heat to a gentle simmer and let the sauce thicken, stirring constantly, 1 to 2 minutes. Season with salt and pepper to taste.
Add the meatballs back to the skillet and simmer for another 3 minutes to finish cooking and warm through.
Serve over cooked egg noodles with a sprinkle of parsley.
