Boil spagetti according to the instructions on the packaging.
Mince garlic, chop tomato and grate parmesan cheese.
Heat some olive oil in a medium hot pan.
Sauté garlic and tomato paste for about 2 min.
Add tomatoes and cook them until mushy. Use a spatula to mush them.
Add tuna, pasta water, miso and parmesan cheese and cook for a few min while stirring.
Season with chili flakes and black pepper.
Lastly, add the cooked pasta and stir to coat the pasta in the sauce.
Enjoy!