Also, you could add a small amount of egg yolk.
Take off the heat again, and beat in the egg yolks.
Add the egg yolks, one at a time, and beat in well.
Keep the egg yolk in one half of the shell.
Add one egg yolk at a time, beating well after each addition.
You may add a raw egg yolk at this time.
Beat the last egg yolk with one tablespoon of water.
I suspect that they at least let it see an egg yolk.
For this form most often only the contents of the egg yolk is used.
Add 1/4 cup of the hot cream mixture to the egg yolks.