In a large bowl, beat together the egg, milk, cornstarch, onion, salt, pepper, and spices like nutmeg, allspice, and ginger.

Add the lean ground beef to the mixture. Mix lightly until combined, being careful not to overwork the meat. Shape into 1-1/2-inch meatballs.

Heat a skillet over medium heat and melt butter. Brown the meatballs in batches for about 10 minutes, turning occasionally until cooked through and golden brown. Remove and let drain on paper towels.

In the same skillet, add a little more butter to the drippings, then stir in the flour. Gradually whisk in the beef broth and milk, cooking until thickened, about 2 minutes.

Return the meatballs to the skillet, coating them in the rich gravy, and heat through. Serve over hot noodles or fluffy mashed potatoes, garnishing with fresh parsley.