1 teaspoon freshly ground black pepper, plus more for finishing
1/2 lb (8 ounces) spaghetti or other long pasta
1 cup finely grated Pecorino Romano cheese, plus more for finishing
Bring a medium pot of water up to a boil using just enough water to cover the spaghetti. Season with salt, but go easy. Drop spaghetti into boiling water and cook according to package directions until very al dente. Reserve 1 cup of pasta water, then drain.
Melt 2 tablespoons butter in a medium skillet, then add the pepper. Swirl around for about 1 minute until the pepper is fragrant and toasted.
Add 1/4 cup of pasta water to the pan and bring up to a boil, then add the pasta and turn off the heat. Add half of the cheese while tossing and swirling the pasta around, then add the remaining cheese and butter. Continue tossing the pasta until it creates a thick, velvety sauce. Add more pasta water a little bit at a time to thin out the sauce as needed. Taste for seasoning and adjust accordingly.
Transfer to bowls and serve immediately with more pepper and cheese on top.