HOW TO TEMPER AN EGG
Tempering an egg prevents the egg from scrambling when it comes into contact with a heated mixture. To temper an egg (or eggs), simply give them a whisk in a separate bowl and drizzle about a tablespoon of your hot mixture into the egg while continuing to whisk. Do this a few a more times so that the eggs slowly heat up. You can now pour the heated egg mixture into your hot mixture and the eggs won’t cook from the heat exposure.
[...] a small amounts of the cream mixture into the sugar and egg mixture until both are mixed together. (See how to Temper an Egg)5. Return mixture to saucepan over medium heat (do not boil) and stir constantly until a custard is [...]