Cut the rind off the guanciale and cut it into cubes. Add it to a cold, dry pan and put the heat on medium.
If making your own Italian sausage, grind the spices and mix into the sausage meat well.
Separate the egg yolks, grate the pecorino and grind the peppercorns and mix together into a paste.
Once the guanciale is crisp and the fat is rendered, remove and set side. Add a couple of spoons of the fat to the egg mix and stir it in.
Crumble the sausage into the pan and fry off in the guanciale fat for 3-5 minutes.
Finely dice the onion and add it to the pan once the sausage has browned off. Cook off for another 3 minutes or so, until soft and golden.
Add in the tomato puree and crushed tomatoes and put your pasta on the boil.
Boil the pasta for around 2 minutes less than instructed. Just before it is done, add a ladle of pasta water into the sauce. Drain the pasta and add it in too and take it off the heat.
With the pan off the heat, add in the egg mix and immediately stir to incorporate. Keep stirring to prevent the egg from scrambling.
Once the sauce has fully incorporated and thickened, serve into bowls and garnish with guanciale.
