Asparagus with Lemon-Parmesan Butter

Fill a heavy-bottomed, 12-inch sauté pan halfway with cold water. Sprinkle with 2 tablespoons salt and bring to a boil over medium-high heat. When the water boils, carefully arrange the asparagus in the pan in a single layer with all the tips facing the same way. Move the pan so the tip end is just off the heat. Cook until the asparagus are al dente, approximately 7 minutes.

Meanwhile, put the lemon juice in a 1-quart saucepan and bring to a simmer over low heat. Remove the pan from the heat and, while still hot, use an immersion blender or whisk to blend in the butter, one cube at a time. Keep the butter sauce at a tepid temperature as you blend it; it should be just warm to the touch. If the mixture gets too cold, return the pan to very low heat for a few seconds, taking care not to overheat it, which will cause the butter to break. Slowly whisk in the Parmigiani-Reggiano and lemon zest and season with salt and pepper.

Remove the asparagus from the water with tongs or a slotted spoon and drain. Transfer to a plate or platter and sauce with the lemon-parmesan butter. Serve hot.