This is one of my son's favorite dishes so, of course, it needed to be included on the menu during his time at home. Because there are very few ingredients, the quality of what you use is of the utmost importance so that the dish really sings. I was unable to find traditional guanciale, but had some delicious double smoked artisanal slab bacon which I substituted. I have also made this with regular bacon and, while not quite the same, it is quite yummy cooked that way as well.
2 portions spaghetti (I always leave that up to you as pasta portion size is subjective)
1 egg yolk + 1 whole egg
3/4 cup small diced slab bacon
1/3 cup Parmesan, grated
1/4 cup Pecorino Romano (or more Parmesan)
1/4 cup pasta cooking water
Salt and white pepper to taste
Put a pot of salted water on to boil for the pasta.
While the water is boiling, mix the 1/3 cup of Parmesan and the eggs together in a small bowl. Set aside. Place a large bowl under the colander into which you will drain your pasta. Place in the sink for later. Dice your slab bacon.
As soon as the pasta water boils, add the spaghetti and cook for 1 minute less than the directions on the package.
Tip your diced bacon into a cold skillet and cook over medium-low heat until the fat has rendered and the pieces of bacon are crisp on the outside and still tender and a bit chewy in the center, a couple of minutes. Set aside.
As soon as the pasta is done, reserve 1/4 cup of the cooking water and drain the pasta, allowing the water from the pasta to drain through the colander and heat the large bowl beneath it.
Put the heat back on low under the bacon, tip the drained spaghetti into the skillet and stir well until the bacon is dispersed throughout the spaghetti. Turn off the heat.
Tip the hot water out of the large bowl and add the spaghetti. Scrape the cheese and egg mixture over the top and stir well to combine. Add an 1/8 cup of the pasta water and continue to stir, bringing the spaghetti up from the bottom of the bowl until a creamy sauce develops and coats each strand of spaghetti. If the sauce is too thick, add some of the remaining pasta water.
Add the remaining cheese, salt and pepper and stir to combine.
Serve at once, preferably in heated bowls for maximum enjoyment.
Inspiration recipe here, with many thanks to all those who commented below it.