Meanwhile render diced bacon. Shortly before it's completely rendered, add chopped onion and garlic slices. Cook until the onion is soft and add cream, pepper flakes, and nutmeg.
When the pasta is cooked, transfer the pasta with a slotted spoon or large sieve directly from the pasta pot to the pan with the bacon. Do not drain the pasta first; you want some of the pasta water in the dish. Add the peas to the hot pasta water to blanch.
Turn off the fire under the pasta and bacon mixture and add the eggs, stirring to thoroughly coat each pasta tube with the egg. Take care not to allow the egg yolks to scramble at the bottom of the pan. Transfer the peas with the slotted spoon or sieve from the pasta water to the pan along with the black pepper and parmesan. Continue to stir. Add pasta water if it appears too dry. Stir until every pasta tube is well coated with the sauce.
Serve with freshly grated parmesan and some sliced green onion on top.