Boil the water: Bring a large pot of lightly salted water to a boil.

Add the spaghetti: Add the spaghetti to the boiling water and cook it until just shy of tender, then reserve 1 1/2 cups of the pasta water before draining.

Toast the pepper: Warm a large skillet over medium heat, add the black pepper, and toast it for about 30 seconds until fragrant.

Start the sauce: Add 3/4 cup of the hot pasta water to the skillet and bring it just to a simmer.

Toss in the pasta: Add the spaghetti and toss for 1 minute so the noodles are coated with the peppery liquid.

Add the cheese: Take the skillet off the heat and add the Pecorino in small handfuls, tossing constantly and adding more pasta water as needed until the sauce turns smooth and glossy.

Serve immediately: Divide the pasta between warm bowls and finish with a little extra pepper if you want a sharper edge.