Begin by melting the unsalted butter in a spacious pot over medium heat. Once melted, add the finely chopped onion and sauté it for about 5 minutes, or until it becomes translucent and softened.
Next, introduce the minced garlic to the pot and continue to sauté for an additional minute, stirring frequently until the garlic is fragrant but not browned.
Gently add the sliced mushrooms into the pot. Cook them while stirring often for approximately 10 minutes, or until they have released their juices and become tender.
Once the mushrooms are well-cooked, sprinkle the all-purpose flour evenly over them. Stir the mixture thoroughly to combine and allow it to cook for about 2 minutes.
Slowly pour in the vegetable broth while stirring continuously to prevent lumps from forming. Bring the soup to a gentle simmer.
Once the soup is simmering, incorporate the dried thyme, followed by a sprinkle of salt and freshly cracked pepper. Allow the soup to cook for about 15 minutes.
After simmering, take an immersion blender and puree the soup until it reaches a smooth consistency.
Now, reduce the heat to low and stir in the heavy cream or coconut cream. Heat the soup gently, adjusting the seasoning with additional salt and pepper as needed.
Ladle the warm soup into bowls and garnish each serving with a generous sprinkle of freshly chopped parsley.
Notes
For a dairy-free option, use coconut cream instead of heavy cream.