1. Bring a large pot of water to a boil and salt it. Add the asparagus and cook until fully tender but not mushy, 8 to 10 minutes. Drain well, reserving some of the cooking liquid, and let the asparagus cool slightly.
2. Transfer the asparagus to a food processor/blender and add the garlic, pine nuts, 2 tablespoons of the oil, Parmesan, a pinch of salt and a couple of tablespoons of the cooking liquid. Process the mixture, stopping to scrape down the sides of the container if necessary, and gradually add the remaining oil and a bit more of the reserved cooking liquid to moisten if necessary. Add the lemon juice and season with salt and pepper to taste, pulse one last time, and serve over pasta, fish or chicken (or cover and refrigerate for up to a day).