Boil up about 2 l salted water in a large pot. Peel onion and garlic, dice finely. Pour pasta into boiling water, stir once and cook for 10-12 minutes
Heat the oil in a pot. Sauté onion and garlic until transparent. Drain the tuna and chop it a little. Deglaze onion with 100 ml water and tomato sauce
Stir in broth. Fold the tuna and olives into the tomato sauce. Heat everything carefully (do not boil!). Season the sauce with salt and pepper
Rinse the basil. Pluck off the leaves, cut into strips and add to the sauce. Drain the pasta and serve with the sauce. Sprinkle with parmesan cheese