Bring a large pot of salted water to boil. Once bubbling, add spaghetti and cook according to package instructions until al dente.

In a large skillet, heat olive oil over medium heat until shimmering.

Add minced garlic and sauté until fragrant, about 30 seconds, being careful not to burn it.

Add asparagus pieces to the skillet, seasoning with salt and pepper, and sauté for about 4-5 minutes until tender but still vibrant and slightly crunchy.

Once pasta is done, reserve about ½ cup of the pasta cooking water, then drain the spaghetti.

Add the drained spaghetti to the skillet with the asparagus.

Sprinkle in the lemon zest and juice, and pour in enough reserved pasta water to combine everything.

Toss gently until well-coated and let the pasta absorb the flavors.

Serve warm, topped with grated Parmesan and a pinch of red pepper flakes if desired.