Ingredients
6 cups hot rich meat broth (chicken, beef, or a combination; freshly made or canned)
2 ounces (1/8 of a 1-pound package) vermicelli
1/4 pound (1/2 cup) unsalted sweet butter, softened
3/4 cup freshly grated Parmesan cheese
4 egg yolks
1 cup heavy cream
Method
Bring the broth to a gentle boil over direct heat. Add the vermicelli (break into shorter pieces if you prefer) and cook uncovered for 5–8 minutes, or until the noodles are tender but still have a slight bite.
While the pasta cooks, combine the softened butter, grated Parmesan and egg yolks in a bowl. Gradually whisk in the heavy cream until the mixture is smooth and homogenous. If you will finish the dish at the table (for example, in a chafing dish), prepare this mixture in the kitchen first.
Temper the cream mixture by spooning a small amount of the hot broth into it while stirring constantly. Once warmed, pour the tempered mixture back into the pot of hot broth and vermicelli, stirring steadily to combine. This will thicken the broth and create a rich, silky texture.
If using a chafing dish, extinguish the flame; if on the stove, remove the pot from the heat. Ladle the soup into bowls and serve immediately, while hot and creamy.