When you put the pasta in the water, you can prepare garlic, parsley, tuna and lemon.
When the pasta is almost ready, put on a plate with a frying pan or saucepan that has room for the pasta and put in the oil.
When the oil is hot. add garlic and let it cook for approx. 30 seconds. Then stir in the tuna. lemon juice and parsley. Add a few tablespoons of pasta water.
Let it get hot and add pasta.
Serve with lemon zest. (Parmesan is not served with fish, but if you like it, GO for it!)