Cut your guanciale into large, thick pieces, 1-2cm. Ensure to remove the skin and the peppered exterior before doing so. Add to a cold pan and turn on the heat to medium high. Allow the fat to slowly render out, stirring regularly to let the meat crisp up evenly.
Put the spaghetti on to boil, and cook for 1-2 minutes less than packet instructions. A minute or two before the pasta is cooked, collect a cup of pasta water and save for later.
Grate the pecorino and mix it in a bowl with the egg yolks and ground black pepper.
Add a few spoonfulls of the fat from the guanciale to the eggs and mix well. Add a few spoonfulls of the pasta water too and do the same. This will temper the eggs to prevent them from scrambling later and start the emulsification.
Remove the guanciale from the pan once cooked and drain off around half of the fat. Turn the heat off.
Once the pasta is ready, remove it from the water and add it straight into the guanciale pan. Toss the pasta in the remaining fat to coat evenly.
Add the egg and cheese mix to the pasta and mix well immediately. The residual heat will cook the eggs. Use the remaining pasta water to thin the sauce out if needed, or add extra cheese to thicken if needed.
Portion the pasta into bowls, scatter the guanciale cubes on top and finish with freshy ground black pepper or freshly grated pecorino as desired!
