3/4teaspoonflaky sea saltlike Maldon or 1/2 teaspoon fine sea salt
2tablespoonseach freshly grated Pecorino Romano and Parmesan cheeseor 1/4 cup of one type, plus additional for serving
1tablespoonfreshly ground black peppercorns
8ouncesdried fettuccine or tagliatelle pasta
1cupshelled fresh or frozen peas
Put the pancetta or bacon in a small skillet over medium-low heat. Cook until the fat is rendered and the pancetta is crisp and golden, about 10 minutes. Remove to a paper-towel lined plate.
Whisk together the egg yolk, mascarpone and flaky salt in a bowl. Zest the lemon into the bowl, then halve the lemon and squeeze the juice of one half into the bowl. Stir in the cheese and black pepper.
While the pancetta is cooking, bring 4 quarts water to a boil in a large saucepan or stock pot and season with 2 tablespoons kosher salt. Add the pasta and cook until al dente. Drop the peas into the pot 2 minutes before draining. Scoop out and reserve 1/2 cup of the cooking water.
Put the hot drained pasta back into the pot and toss with the butter until it melts. Whisk 1/4 cup of the cooking water into the egg yolk mixture until smooth, then pour over the pasta and toss together with tongs. Drizzle in more water if the sauce seems too thick (keep in mind it will thicken as it sits).
Add the pancetta to the pasta and toss gently to disperse. Serve the pasta with additional cheese.
I use a mixture of grated cheeses in this recipe - sheep's milk Romano and Parmesan. If you don't have both kinds on hand, use just one of them instead.
Tellicherry peppercornshave the best flavor, with rich, warm heat and beautiful aroma. Grind them in a spice grinder just before making the pasta.
The recipe will satisfy 2 to 4 people (it's pretty rich). If you want to make sauce for a pound of pasta, double up on the ingredients, but use discretion with the black pepper so it doesn't overwhelm the dish — try 1 1/2 tablespoons at first and taste.