Set a large pot of water to boil for pasta.
Slice the guanciale (or bacon) into thin slices.
In a large deep saute pan, fry the bacon slices naked – meaning no oil. Note: It’s not necessary to use oil because you want the grease from the bacon to create the base and flavor of this dish. After about a minute, the fat will begin to liquefy creating a shallow pool of clear grease. Continue to cook until the bacon becomes crispy. Turn off heat and let rest until other ingredients are ready.
In the large pot, bring water to boil. Add salt to boiling water, then add the dried pasta.
While the pasta cooks, prepare your eggs. In a bowl, separate the egg yolks. (Store whites in fridge for later use in another dish.) Add a generous pinch or two of grated black pepper and beat the eggs. Add two handfuls of freshly grated Pecorino Romano and mix well to a sandy, custard-like texture.
When pasta is done cooking. Turn off the heat and DO NOT dump the pasta water. Using a large mug, conserve some of that pasta water, set it aside. Using tongs, pull spaghetti from water (or drain the spaghetti) and drop them immediately into the deep pan of bacon and grease. With the flame still off (or you can put it on a very low flame just to warm it up a bit but don’t leave it on) stir the pasta, coating it with all the grease.
Add the egg cheese mixture and continue to stir, coating the pasta.
Now, to get that creamy texture: Using the mug of conserved pasta water. Continue stirring the pasta and add a the pasta water a bit at a time. You will see the grease, egg and water amalgamate, creating that rich thickness. Continue stirring gently while adding another hand full of Pecorino Romano. Continue stirring. Add a bit more water. Stir. Another handful of Pecorino, keep stirring. Shortly, you will see a gorgeous creamy coating on your pasta. You’re done.
Serve immediately on flat plates. Sprinkle with more Pecorino Romano, top with freshly grated pepper and a tiny sprinkle of parsley. Accompany the dish with a glass of basic red table wine.