01 -
Bring a large pot of water to a boil and salt it well. Add the spaghetti and cook until about 1 minute shy of al dente. Reserve 1 cup of the pasta water, then drain.
02 -
While the pasta cooks, heat the olive oil in a wide skillet over medium-low heat. Add the sliced garlic and cook for 2-3 minutes, stirring often, until the edges are pale gold.
03 -
Stir in the red pepper flakes for about 20 seconds. If the garlic is coloring too quickly, remove the skillet from the heat.
04 -
Add 1/2 cup reserved pasta water to the skillet and swirl carefully. Let it bubble for 30-60 seconds so the oil and starch begin to come together.
05 -
Add the drained spaghetti to the skillet. Toss over low heat for 1-2 minutes until glossy, adding more pasta water a few tablespoons at a time if needed.
06 -
Turn off the heat and toss in the parsley. Taste and adjust salt. Rest for 1 minute, then serve hot with extra chili flakes if you like.