Made my "foolproof" way. Cooking the pasta in minimal water to maximize the starch content. The extra starchy water makes it much less likely that the cheese + water emulsion will separate. Honestly, it was just okay. It had a somewhat unpleasant tart flavor. Not sure where that came from. I used authentic Italian Pecorino Romano.
Not shown: I toasted the whole peppercorns, and then ground them in mortar + pestle.
by SmasherOfAjumma