Mix the ground beef with the egg and half of the chopped onion. Season with one stock cube and black pepper.
Pour olive oil into a large pot and heat. Roll the meat mixture into the size of ping pong balls and add them to the oil. Fry until almost done then add the rest of the onion and fry together for another couple of minutes.
Add tomatoes to the meatballs; add the red wine, the other stock cube and black pepper to season. Let everything simmer for another 15 minutes.