Mix ground beef, chopped onion, salt, pepper, and beaten egg together (I use my hands)
Form into balls about 1 or 2 inches in diameter.
Brown in electric skillet set at about 325 degrees. You don't want to completely cook them, just brown them
Add 1 cup of water, lower the heat to a simmer setting and cover the skillet. Cook about 20 minutes or until one of the larger meatballs is cooked through.
Meanwhile, cook potatoes for mashing or noodles.
When meatballs are cooked through, remove from skillet.
Mix flour and COLD water and add to the liquid in the skillet to make a roux. Let cook until it starts thickening and add milk to make about 2 cups of gravy. Let cook 5 minutes or until the gravy is thick.
Pour gravy over meatballs and serve with noodles or mashed potatoes.