Spaghetti Al Limone with Asparagus

Cook pasta in a large pot of boiling salted water, stirring occasionally, until al dente. Drain pasta, reserving 1½ cups pasta cooking liquid.

While pasta cooks, heat oil in a large heavy pot over medium-high heat, until shimmering. Add asparagus, season with salt, and cook, stirring often, until just beginning to take on color, (about 1 minute). Add garlic, lemon zest, and red pepper flakes and cook, stirring, until fragrant, (about 30 seconds). 

Remove from heat and let sit until pasta is done.  Add pasta and basil to pot with asparagus mixture and return to medium-high heat. Squeeze juice from both lemons into pot and add 1/4 cup Parmesan and 1 cup reserved pasta cooking liquid. Cook, tossing vigorously and adding more pasta cooking liquid if needed, until sauce is creamy and emulsified and pasta is coated, (about 1 minute). Taste and season with more salt if needed. Remove and discard garlic.

Divide pasta among bowls, placing a lemon zest strip in each, and top with more Parmesan.