Bring a large pot of salted water to a rolling boil, then add the pasta. Cook until just al dente, about 8 minutes, stirring occasionally. Drain, reserving a cup of pasta water, and set aside.
While the pasta cooks, trim the woody ends off the asparagus and cut the spears into halves or thirds for even cooking.
Heat a large deep skillet over medium heat, then add the butter and olive oil. Let them melt together until shimmering and fragrant, about 1 minute.
Add the trimmed asparagus to the skillet and sauté for 3-4 minutes, stirring occasionally, until they turn bright green and become tender but still crisp. You should hear a gentle sizzle and smell fresh grassy aroma.
Push the asparagus to one side of the pan, then add the minced garlic to the cleared space. Cook for 30 seconds, stirring constantly, until the garlic is just golden and fragrant.
Pour in the fresh lemon juice and sprinkle the lemon zest into the skillet. Stir everything together and cook for another 30 seconds, allowing the flavors to meld and brighten the butter sauce.
Add the drained pasta directly into the skillet with the asparagus and lemon butter. Toss everything together gently using tongs, coating the pasta evenly with the sauce. If the mixture seems too thick, splash in a little reserved pasta water, a tablespoon at a time, until it becomes silky and glossy.
Season with salt and freshly cracked black pepper to taste. Taste and adjust lemon or seasoning as desired, aiming for a vibrant, balanced flavor.
Finish by adding a small pat of butter or a splash of olive oil for extra shine and richness. Give everything one last toss to incorporate.
Serve immediately, garnished with additional lemon zest or herbs if desired, and enjoy the bright, buttery flavors and tender asparagus in every bite.
