Place the onion and parsley in a large bowl with the meat, salt to taste, and half the paprika and cumin. Mix well and form into balls the size of a walnut. Set aside.
Pour the oil into a tagine and add the passata, salt and pepper to taste, and the remaining spices. Cook for 2 minutes, then add the tomato paste and water and cook until the sauce bubbles.
Place the meatballs carefully in the tagine and stir until they are sealed on all sides. Break the eggs over the meatballs and leave to bubble gently over a very low heat until the eggs are cooked.
Serve once the sauce has reduced.