Saute pancetta in very little olive oil. When pancetta is browned, add the stock.
At this stage remove the pan and keep aside and cook the spaghetti in hot salted water as per instructions on the packet.
When done add the spaghetti to the pan with the stock. Add the parmesan cheese and pour in the beaten egg yolks while vigorously tossing the pasta. Turn off the heat.
Season with pepper; add salt to season only if required.
Toss the pasta with a final drizzle of a little extra virgin olive oil.