1. Base ingredients like oil and pork (in the case of carbonara, that would be guanciale or pancetta) should be cooked in a skillet first, to render the fat, but once you've done that, the contents of the skillet should be transferred to a big bowl and allowed to cool a bit.
2. Then you can add the grated cheese and the eggs, which should be at room temperature.
3. Next, use a wooden spoon to vigorously stir the ingredients together to make a thick, custardy sauce.
4. Finally, transfer your just-cooked pasta to the bowl and toss it with the sauce, adding a little pasta water as you go, until the sauce is creamy and coats the noodles.