Mince the garlic by cutting it in half lengthwise and removing the core.

Boil water in a pot, add salt (not listed in ingredients), and cook spaghetti 1 minute less than the package instructions. Reserve 2 tbsp of pasta water and drain the spaghetti.

Heat olive oil in a frying pan, add minced garlic, and sauté over low heat until fragrant. Add dried shirasu and stir over medium heat until coated with oil.

Add spaghetti, reserved pasta water, lemon juice, butter, salt, and black pepper to the pan. Stir until the butter melts and everything is well combined.