01 -
Fill a big pot with water, add salt, and bring it to a boil. Toss in the penne and cook per the package directions until just firm. Save 1 cup of the pasta water, then drain and set aside.
02 -
As the pasta boils, warm olive oil in a pan over medium heat. Stir in the garlic and cook for about a minute until it smells amazing. Toss in the asparagus pieces and cook, stirring for 5-7 minutes, until they're tender with a bit of crunch.
03 -
Lower the heat and add the penne to the pan with the asparagus mixture. Drizzle in the lemon juice and sprinkle over the zest. Stir well, adding a bit of the reserved pasta water at a time to make it saucier.
04 -
Taste and add a bit more salt or black pepper if needed. Top with grated Parmesan and a pinch of chili flakes, if you like, right before serving.