Heat oil in a pan then add the diced onion and salt. (Traditional Carbonara recipes don't call for onion but onion is always good.) Saute the onion on high heat for 5 minutes until it gets a glassy, translucent look.
Add the bacon, garlic and black pepper. If we cook with Pancetta or Guancale the process needs to be started with rendering the fat out of the meat and adding the onion after when there is enough fat to saute it. Also the fried bits of meat needs to be taken out while preparing the onion.
Turn the heat down to stir-fry the bacon and the onion until the onion slightly caramelizes and gets a brownish color in about 15 minutes.
Pasta
Put the ingredients into a bowl and mix it well.
The mixture shouldn't be runny nor dry to the touch but between that, it's gonna be good to go.
Fill a pot halfway up with water and add ½ teaspoon/cup or 10g/liter Salt. Put the lid on and bring it to boil. Use something with holes on like the opposite side of a shredder with big holes and a spatula or make the dumplings with a small spoon. (Check out our KitchenBazaar in the Reviews section for spatzel maker)
The dumplings will submerge upon getting into the water and float back up when cooked in about 30 seconds or less. Take the surfaced pasta out from the cooking water and continue with the next batch.
Assembly
Add the pasta to the onion, bacon, garlic and black pepper in the pan then stir-fry it on medium heat for a couple of minutes until all the ingredients are mixed well and uniformly heated.
Crack the eggs and beat them up in a bowl with the grated hard cheese. Take the pan off heat and pour the egg right into the pasta while continuously stirring. Mind not to have a too hot pan as that will fry the eggs and we end up having fried egg noodles which is also a fine dish but far from Carbonara.
Serve immediately onto plates to avoid clogging of the egg.