In a large skillet, melt the butter over medium heat. To make the roux, whisk in the flour, a little at a time, until you have a smooth, thick paste.

Slowly whisk in the beef broth about ½ cup at a time until the mixture is smooth and still quite thick. Simmer for a couple minutes, add the seasonings and give it a quick taste. Adjust seasoning as needed.

Stir in the ground beef, onion, and parsley. Cook the mixture for about 4 to 5 minutes or until the beef is mostly cooked through. Adjust seasoning if needed.

Remove from the heat and transfer the mixture to a shallow container. Cover and refrigerate for at least 3 hours, preferably overnight, to allow the mixture to solidify.

Prepare your breading station by placing the flour, beaten eggs, and breadcrumbs into 3 wide bowls. Use a medium cookie scoop to portion out the meat and shape into small balls.

Bread the balls one by one by rolling each through the flour, then through the egg, and then through the breadcrumbs. Arrange the breaded balls on a sheet pan.

Heat oil in a Dutch oven to 375°F/190°C. Fry the meatballs in small batches for about 2 ½ minutes until golden. Remove to a paper towel-lined tray to soak up excess oil.