I start by heating olive oil and butter in a large pot. Once hot, I toss in diced onions with a little salt and cook them until soft. Then I add mushrooms in two batches so they brown nicely without steaming.
This step takes about 10 minutes, and it’s where the magic begins because the mushrooms release their savory juices.
Next, I stir in the garlic and let it cook for a few seconds until fragrant. I then deglaze the pot with white wine, scraping up the browned bits from the bottom.
This adds so much flavor! After that, I pour in the broth, tamari, and thyme sprigs. Once it comes to a boil, I lower the heat and let it simmer for about 15 minutes so everything blends together beautifully.
When the soup has cooled slightly, I blend about two-thirds of it until smooth and then pour it back into the pot. This way, it’s creamy but still has little chunks of mushrooms for texture.
At this point, I stir in the cream for an extra indulgent touch. Finally, I season it with salt and pepper, and it’s ready to serve hot.