Heat 1 tablespoon of oil in a skillet (frying pan), add the onion and garlic, and cook for 5-8
minutes until soft. In a bowl, mix with the beef, bread crumbs, egg yolk, 1 tablespoon of tomato
paste, and seasoning. Form the mixture into 3cm / 1 1/4 inch balls. Heat the remaining oil, add the
meatballs, and pan-fry for 10-15 minutes until golden brown all over.
Mix the tomatoes, stock, and remaining tomato paste together. Season, then bring to a simmer and
cook for 5 minutes until the sauce begins to thicken. Add the meatballs and continue to simmer.
Meanwhile, bring a saucepan of water to a boil, add the spaghetti, and cook for 10-12 minutes,
or until al dente. Divide the pasta among 4 bowls, top with the meatballs and sauce, garnish with
parsley, and serve with bread.