In a large pot, pour in water, salt and oil and bring into a boil.
Once boiling, drop in spaghetti pasta.
Cook pasta for 8-10 minutes.
Drain pasta and set aside.
In a large pan or skillet, heat olive oil.
Sauté garlic and onion.
Once onions are translucent, add in tomatoes.
Pour in tuna flakes then mix.
Season with salt and black pepper.
Add in chopped parsley and continue to mix.
Toss in pasta and mix until sauce is distributed well on the pasta.
Sprinkle parsley on top.
Serve and enjoy.