Boil the pasta. Bring a large pot of salted water to a rolling boil. Add the pasta and cook until just shy of al dente according to the package. Before draining, reserve 1 cup of pasta water.

Prep the sauce base. While the pasta cooks, scoop the avocado flesh into a blender or food processor. Add the lemon zest and juice, garlic, olive oil, a pinch of salt, and a few grinds of black pepper.

Blend until creamy. Start blending and drizzle in a few tablespoons of hot pasta water to create a smooth, pourable sauce. Aim for a consistency similar to thin Alfredo. Add more water as needed. Taste and adjust salt, pepper, and lemon.

Add cheese and herbs. Pulse in the Parmesan and herbs until just combined. If you’re keeping it dairy-free, skip the cheese and add a tablespoon of nutritional yeast for a savory note.

Toss with pasta. Return the drained pasta to the warm pot. Pour over the avocado sauce and toss over low heat for 30–60 seconds, adding splashes of pasta water until the sauce clings to the noodles. Do not cook the sauce for long; just warm it through.

Finish and serve. Plate the pasta and top with extra Parmesan, red pepper flakes, a drizzle of olive oil, and any add-ins like roasted cherry tomatoes or toasted pine nuts. Serve immediately while it’s silky and bright.