Julia Child’s Cream of Mushroom Soup

Heat half of the butter in a 3.5-quart dutch oven or heavy duty pot over medium heat.

Add the onion and turn to medium-low heat. Cook and stir onion until tender and translucent, about 8 minutes. Do not brown the onion.

Add flour and continue stirring over medium-low heat for 3 minutes, until the flour and onion are well combined.

Add the chicken stock, about one cup at a time. Stir constantly until it forms a silky paste and starts simmering.

Add the parsley, bay leaf, and thyme. Simmer over medium-low heat, partially covered, for 15 to 20 minutes, until the soup reaches the desired thickness.

While simmering the broth, cook the mushrooms.

Melt the remaining 2 tablespoons of butter in a large skillet until the butter starts to bubble.

Add mushroom slices and season with salt. Stir a few times to mix well.

Cook, stirring occasionally, until the mushrooms are browned, about 5 minutes.

Add the mushrooms into the soup.

Combine the egg yolks (if using) and heavy cream in a small bowl and beat until mixed well (*Footnote). Slowly add the cream-yolk mixture into the broth.

Adjust the seasoning with salt and more cream if necessary. Heat over lowest heat for another 5 minutes. Do not bring the soup to a simmer.

Garnish with chopped parsley or croutons. Serve hot.