If using pancetta, fry pancetta in a little oil and butter. If using Guanciale, it's not needed. Cook until crispy. Remove from heat (this is important!)

Cook pasta in salted water, as per instructions, be ready to drain 1 min before end of cooking time (important too) meanwhile beat eggs and 4 spoons of Parmesan together

Drain pasta 1 min before cooking time. Add immediately to the pan. Add eggs immediately. Mix very well on a low heat for just 1 min, no more. The heat from the pasta cooks the eggs and makes it creamy (no cream in the recipe, common misconception) the pan with the meat must be cool when you add pasta and eggs otherwise the eggs will scramble.

Serve with black pepper