Bring a large pot of water to a boil. Add sea salt to the water. Cook the asparagus 1 - 2 minutes, then remove to a bowl of ice water. Add the spaghetti to the boiling water and set a timer for two minutes less than the shortest recommended cook time.

When asparagus is cool enough to handle, cut it lengthwise into thin, 1/8-inch thick strips.

Meanwhile, in a deep, wide pot big enough to hold the pasta, melt the butter over medium heat and stir in the pepper. The butter and pepper mixture will bubble and bloom, once fragrant, turn heat to low.

When the pasta is almost done, use a measuring cup to pull 1 cup starchy pasta water from the pot and add it to the butter mixture. Turn heat to medium-high and bring to a vigorous simmer. Stir often as the butter and pasta water reduce to a creamy, light brown sauce. Keep over low heat.

When the pasta's done, scoop it out of the water with your spaghetti spoon and toss it, along with the asparagus, in the pot with the creamy sauce. With your spaghetti spoon and maybe a second wooden spoon, work quickly to fold the cheese into the hot pasta. Add a splash more pasta water as needed.

Serve pasta immediately in big twists, garnish with lemon zest and more pepper.