Bring a large saucepan of water to the boil. Add 1-2 tsp salt.
Cook the chopped bacon or pancetta in a frying pan over medium heat until crispy. Set aside.
Cook the fettuccine pasta in the pot of boiling water according to the packet instructions, until al dente.
Meanwhile, beat the eggs in a medium sized bowl. Add the parmesan cheese and mix well.
When the pasta is cooked, use tongs to remove it from the pot of boiling water and straight into the frying pan with the pancetta (don't throw away the water!).
Put the frying pan over a medium heat and add 1/4 cup of the reserved pasta water.
Shake the pan for 10 seconds or until most of the water has evaporated.
Remove the pan from the heat and pour in the egg/cheese mixture.
Working quickly, stir the pasta until it has a smooth coating from the sauce.
Add in a little more of the pasta water if the egg mixture is too thick.
Season with sea salt (if needed) and cracked pepper and serve immediately.