Don't let the ridiculously short ingredient list fool you -- this pasta is incredibly flavorful and oh-so-comforting. That, and the fact that you can throw it together in about 20 minutes just might make it your new favorite weeknight meal.
The key to an authentic cacio e pepe lies in the emulsion of cheese, pasta water, and fat. Ensure your Parmesan is freshly grated – pre-grated cheese often contains anti-caking agents that hinder a smooth sauce. Use a very coarse grind for the black pepper; it provides textural contrast and a more robust flavor. Toasting it briefly in the butter and oil helps release its aromatics. The reserved pasta water is crucial. Its starch content helps thicken the sauce and create that signature creamy texture. Add it gradually, tossing vigorously, until the sauce coats the pasta beautifully. A rapid, continuous toss is essential for emulsification. Serve immediately, as the sauce can tighten as it cools. Finish with an extra grind of pepper and a sprinkle of Parmesan.