01 -
In a large pot, melt the butter with the olive oil over medium heat. Add the diced onion and sauté for 3-4 minutes, until softened and translucent. Add the minced garlic and fresh thyme (or dried thyme) and cook for another 1-2 minutes until fragrant.
02 -
Add the sliced mushrooms to the pot. Cook, stirring occasionally, for 8-10 minutes, until the mushrooms release their moisture and become soft and browned. If desired, deglaze the pot with a splash of white wine or sherry at this point, scraping any brown bits from the bottom of the pot for extra flavor.
03 -
If a thicker soup is preferred, sprinkle the flour over the mushrooms and stir well to combine. Cook for 1-2 minutes to eliminate the raw flour taste. This will thicken the broth as it simmers.
04 -
Pour in the vegetable or chicken broth and bring the soup to a simmer. Let it cook for 10-15 minutes, allowing the flavors to develop and the soup to reduce slightly.
05 -
For a smoother texture, use an immersion blender directly in the pot to blend the soup until creamy, leaving some chunks for texture if preferred. Alternatively, transfer the soup to a regular blender in batches, then return it to the pot.
06 -
Stir in the heavy cream (or half-and-half for a lighter version) and cook for an additional 3-5 minutes until heated through. Taste the soup and adjust the seasoning with salt and pepper as needed.
07 -
Ladle the soup into bowls and garnish with fresh parsley. Serve with crusty bread or grated Parmesan if desired.