Prepare the meatballs: In a small bowl, combine the breadcrumbs and milk. Let it sit for about 5 minutes until the breadcrumbs soften. This step is crucial for moist meatballs.

In a large mixing bowl, add the ground beef, softened breadcrumbs (discard any excess milk if the mixture seems too wet), the beaten egg, grated Parmesan cheese, chopped parsley, 2 minced garlic cloves, 10g (2 tsp) salt, and 2g (1/2 tsp) black pepper. Ensure your hands are clean before mixing.

Gently mix the ingredients with your hands until just combined. Be careful not to overwork the mixture. Overworking can make the meatballs dense and tough.

Roll the meatballs: Lightly wet your hands to prevent sticking. Roll the meat mixture into meatballs, about 3.8cm (1.5 inches) in diameter. You should get about 20-24 meatballs. Place them on a plate or baking sheet.

Prepare the tomato sauce base: Heat 30ml (2 tbsp) of olive oil in a large, heavy-bottomed pot or Dutch oven over medium heat. Add the finely chopped yellow onion, carrot, and celery (this mixture is called a soffritto). Sauté, stirring occasionally, until the vegetables are softened and translucent, about 8-10 minutes. Do not let them brown.

Add the remaining 3 minced garlic cloves to the pot and cook for another minute until fragrant. Be careful not to burn the garlic.

Stir in the tomato paste and cook for 1-2 minutes, stirring constantly. This helps to deepen its flavor and color.

Pour in the crushed tomatoes and beef broth (or water). Add the dried oregano, dried basil, bay leaf, and the optional sugar if using. Stir everything together to combine.

Bring the sauce to a gentle simmer. Season with 5g (1 tsp) salt and 2g (1/2 tsp) black pepper, or to your taste. Remember that the meatballs also have salt, so season cautiously at this stage.

Gently add the rolled meatballs to the simmering tomato sauce. Ensure they are mostly submerged. If the sauce seems too thick, you can add a little more broth or water (about 120ml or 1/2 cup).

Cover the pot, reduce the heat to low, and let the meatballs simmer gently in the sauce for at least 30-45 minutes, or until the meatballs are cooked through and tender. Stir occasionally to prevent sticking.

Remove the bay leaf before serving.

Serve the meatballs hot, spooning plenty of the rich tomato sauce over them. Garnish with fresh basil leaves if desired. This dish is excellent served with spaghetti, linguine, or any pasta of your choice, or with crusty bread for dipping.