In a medium bowl, combine lean ground beef, egg, chopped onion, minced garlic, Panko breadcrumbs, nutmeg, chopped parsley, and a sprinkle of salt and pepper. Mix until just combined.

Shape the mixture into approximately 20 meatballs, about 1 inch in diameter, and place them on a lined plate or tray.

Heat olive oil in a large skillet over medium-high heat. Add the meatballs in a single layer and cook for 5-7 minutes until browned on all sides. Transfer to a plate.

In the same skillet, pour in beef broth, condensed cream of mushroom soup, and sour cream. Stir until smooth and bring to a gentle boil for 2-3 minutes.

Return meatballs to the skillet and cover to simmer for 5-7 minutes until cooked through and sauce thickens.

Serve the meatballs over freshly cooked pasta with extra sauce and garnish with parsley.