Cook the pasta until al dente.
Beat the eggs and add black pepper and Parmesan. Keeping a small handful of Parmesan back for sprinkling over later.
While the spaghetti is cooking, fry the pancetta with the garlic.
Drop the butter into a large frying pan and, tip in the pancetta and garlic as soon as the butter has melted. Cook until the pancetta is golden and crisp.
Add in the bell peppers or fry them in a different pan, as the bell peppers can add more moist. It depends on how lazy you are.
When the pasta is ready, lift it from the water with a pasta fork or tongs and put it in the frying pan with the chorizo. Don’t worry if a little water drops in the pan as well (you want this to happen) and don’t throw the pasta water away yet.
Take the pan of spaghetti and chorizo off the heat. Now quickly pour in the eggs and cheese. Using the tongs or a long fork, lift up the spaghetti so it mixes easily with the egg mixture, which thickens but doesn’t scramble, and everything is coated.
Add extra pasta cooking water to keep it saucy (several tablespoons should do it). You don’t want it wet, just moist. Season with a little salt, if needed.
Serve immediately with a little sprinkling of the remaining cheese, the bell peppers and a grating of black pepper.