Dice the onion and finely chop the garlic.

Wash the spinach, drain, and cut into thin strips.

Sauté the onion in a pan with plenty of olive oil.

Add the garlic and spinach, and incorporate a bit of salt.

Meanwhile, bring water to a boil for the pasta.

Add the tuna to the onion, garlic, and spinach, and season with pepper to taste.

Finally, add the heavy cream and black olives. Let it cook for a few minutes until the sauce reaches the desired thickness.

Add the pasta to the boiling water and add a bit of salt.

Done: serve the spaghetti on a plate, pour the sauce over it, and finally, top with grated Parmesan cheese.