01 - Bring a large pot of generously salted water to a rolling boil. Add the fettuccine or tagliatelle and cook until al dente, following package directions. Reserve approximately ½ cup of the pasta cooking water before draining the pasta thoroughly.
02 - While the pasta is cooking, prepare the asparagus. Using a vegetable peeler, carefully shave the asparagus stalks into long, thin ribbons. Set the asparagus tips aside.
03 - In a large skillet set over medium heat, combine the extra-virgin olive oil and unsalted butter. Once the butter has melted and is shimmering, add the finely chopped shallot and minced garlic. Sauté for approximately 2 minutes, until the aromatics are fragrant and softened, without browning.
04 - Add the asparagus ribbons and reserved tips to the skillet. Sauté gently for 2-3 minutes, just until the asparagus is tender-crisp and retains its vibrant green color.
05 - Reduce the skillet's heat to low. Add the drained pasta to the skillet with the asparagus. Toss gently to combine the pasta and vegetables. Stir in the lemon zest, freshly squeezed lemon juice, and grated Parmesan cheese. If the sauce appears too thick, gradually add small amounts of the reserved pasta water to achieve a silky, emulsified consistency.
06 - Season the pasta dish generously with salt and freshly ground black pepper to your preference. Divide the pasta among serving plates. Garnish with additional lemon zest prepared in confetti-style strips and freshly chopped parsley. Serve immediately, offering extra grated Parmesan cheese on the side.