Wash the thyme, shake it dry, remove the leaves, and finely chop them.
Peel and finely dice the onion and garlic. Place them in a bowl with the thyme and ground meat. Season generously with salt, pepper, fennel, and paprika, and mix everything well. Shape the mixture into balls about 4 cm in size.
For the sauce, peel and finely dice the onion. Heat the oil in a deep pan and sauté the onions until translucent. Add the tomatoes, season with salt, pepper, and herbs, and let it simmer for about 10 minutes.
Place the meatballs into the sauce and cook covered for about 10 minutes.