Prepare the ingredients: Clean the mushrooms with a damp cloth, then slice them thinly. Chop the onion and garlic.
Sauté the aromatics: In a large pot, heat the olive oil over medium heat. Add the onion and garlic and sauté for 3-4 minutes until they soften, but not browned.
Cook the mushrooms: Add the sliced mushrooms to the pot. Sauté for 7-10 minutes, until they release their moisture and become golden brown.
Deglaze with white wine: Pour in the white wine and cook for 1-2 minutes to let it reduce and infuse the soup with flavor.
Add the broth: Pour in the vegetable broth and bring to a boil. Reduce the heat and let it simmer for 15 minutes, allowing the flavors to meld together.
Blend the soup: Use an immersion blender to puree the soup until smooth. Alternatively, you can transfer it to a blender in batches. Be careful when blending hot liquids!
Finish with cream: Stir in the heavy cream and season with salt and pepper to taste. Simmer for another 2-3 minutes, then remove from heat.
Serve and garnish: Ladle the soup into bowls and garnish with chopped parsley or a dollop of sour cream for added richness.