Steps
1. In a pot, melt butter over medium heat. Add onions and garlic, sauté until fragrant.
2. Add sliced mushrooms, cook until they release their juices.
3. Pour in vegetable broth, bring to a simmer, and let it cook for 15 minutes.
4. Use an immersion blender to puree the soup until smooth.
5. Stir in heavy cream, season with salt and pepper.
6. Serve hot, garnished with fresh parsley.