Sauté the Vegetables:

Heat the olive oil in a large pot over medium heat. Add the diced onion and cook for about 4-5 minutes until softened and translucent. Add the minced garlic and cook for an additional 1 minute until fragrant.

Cook the Mushrooms:

Add the sliced mushrooms to the pot and cook, stirring occasionally, for 5-7 minutes until they release their moisture and start to brown. If you want a thicker soup, you can stir in 1 tablespoon of flour at this point to create a roux. Cook for an additional 1-2 minutes to eliminate the raw flour taste.

Add Broth and Herbs:

Pour in the vegetable or chicken broth, and stir in the dried thyme, salt, and pepper. Bring the soup to a simmer and cook for 10-15 minutes, allowing the flavors to blend together.

Blend the Soup (optional):

For a smoother texture, you can blend the soup using an immersion blender directly in the pot until smooth, or transfer the soup in batches to a stand blender. If you prefer a chunkier soup, you can skip this step and leave the mushrooms as they are.

Finish with Cream:

After blending (if desired), return the soup to the heat and stir in the heavy cream. Simmer for an additional 5 minutes, adjusting seasoning with more salt and pepper if necessary.

Serve:

Ladle the soup into bowls and garnish with fresh chopped parsley for a burst of color and flavor.