Handful of chopped fresh parsley, can use dried parsley as well
Salt and freshly ground black pepper
INSTRUCTIONS
Heat a large pot of water and season with salt (1 litre of water : 1 tablespoon of table salt).
Drain the tuna chunks and reserve the oil. Measure 7 tablespoons of oil and heat in a small frying pan over medium heat.
Once the water has come to a boil, add in the dried spaghetti and cook according to the directions on the package until al dente.
Add the garlic and chilli into the frying pan and turn the heat down to low. Cook, stirring frequently, until the garlic has turned into a light golden brown, which will take about 7 to 10 minutes. Add in the tuna chunks and break them up into smaller pieces and allow the tuna to be heated through. By now the spaghetti should be cooked.
Reserve about 1 cup of pasta water. Drain the spaghetti and return back into the pot. Add in the oil-garlic-chilli-tuna mixture, lemon juice, Parmesan cheese and parsley. Toss and season with salt and black pepper. Add the pasta water, little by little, to get a smooth consistency (you will not need all the pasta water).