Step 1

Clean the mushrooms by wiping them with a damp paper towel. Do not rinse them as they will absorb water. Slice them thinly.

Step 2

In a large pot over medium heat, melt the butter. Add the onion and garlic, and sauté until the onions are translucent and softened, about 5 minutes.

Step 3

Add the sliced mushrooms to the pot and cook, stirring occasionally, for another 5-7 minutes, or until the mushrooms have released their liquid and started to brown.

Step 4

Sprinkle the flour over the mushrooms and stir well to combine. Cook for another 1-2 minutes.

Step 5

Gradually add in the chicken broth, stirring continuously, so that no lumps form. Increase the heat and bring the mixture to a boil. Once it's boiling, reduce the heat to a simmer.

Step 6

Let the soup simmer for about 20 minutes. The mushrooms should be very tender and the flavors well combined.

Step 7

Use an immersion blender to puree the soup until it's as smooth or chunky as you like. If you don't have an immersion blender, you can transfer the soup to a regular blender in batches, but be careful because hot soup can cause a blender to splatter. Always allow the soup to cool a bit before blending it and never fill the blender more than halfway.

Step 8

After blending, return the soup to the pot (if necessary) and stir in the heavy cream. Heat the soup for another 2-3 minutes, until it's heated through.

Step 9

Season the soup with salt and black pepper to taste.

Step 10

Ladle the soup into bowls and garnish with fresh parsley and/or thyme before serving.