First, bring water to a boil and cook spaghetti 1-2 minutes less than directed. Be sure to salt water heavily.
While pasta cooks, prepare the oil. Heat oil over medium-high heat in a large saucepan. Add in the garlic, red chili slices or flakes, and garlic salt. Heat until garlic is sizzling and fragrant but NOT burnt. Add in about ½ cup of the pasta water, stirring continuously.
As soon as the spaghetti are cooked, drain {save the pasta water} and add in to the hot oil. Saute for 1-2 minutes and serve. Add more salt to taste. Serve topped with freshly grated parmesan or a sprinkle of nutritional yeast.
*NOTE - if you're feeling extra lazy, you can sub the fresh garlic and fresh chili for garlic powder and chili flakes. And yes, you can even heat the oil in the microwave in a pinch!!*