Mix well the ground beef, breadcrumbs, egg, garlic, onion, salt, pepper, oregano and basil. Form small balls approx. 3 cm in diameter. Stand on its side.
For the sauce: fry the chopped onion and garlic in olive oil. Add the carrots and mushrooms. Steam for about 2 minutes. Deglaze with the tomatoes pureed in the blender. Add the chunky tomatoes plus the spices.
Add the powder and tomato paste. Since everything simmers for a long time, add some water or red wine if necessary. Bring to a boil, then add the meatballs. Stir carefully and let everything simmer over a low heat for about 3 hours. Preferably without a lid so that the sauce thickens.