Mushroom bisque is full of cream and garlic-infused mushrooms, all blended to make a thick, rich, and beyond flavorful soup! You will want to drink this straight from your bowl!
Add 4 tablespoons unsalted butter to a 6 or 8-quart Dutch oven and melt over medium heat. Once the butter is melted, add 20 ounces sliced mushrooms. Cook and stir the mushrooms for about 5 minutes until they have released a lot of liquid. Turn the heat to medium-low and cook for an additional 10-15 minutes until the liquid has almost entirely evaporated.
Add ½ cup diced onion,2 teaspoons minced garlic, 1 teaspoon fresh thyme, and 1 teaspoon fresh parsley, , and cook for 2-3 minutes, until the onions start turning translucent and the garlic is fragrant.
Turn the heat back up to medium and stir in ¼ cup all-purpose flour. Continue to stir as you cook the flour with the mushroom mixture for 3-4 minutes. It will get clumpy and stick together, which is alright.
Slowly stir in 3 cups chicken broth, ensuring the mixture doesn’t clump up too much as you add it.
Add 1 ½ cups heavy cream and stir until combined.
Carefully ladle the soup into a high-speed blender. Place a clean, folded kitchen towel on top to prevent leaking, and then blend the soup on high speed until smooth. This may be split into a few increments if your blender is not big enough for all of the soup at one time.
Add the pureed soup back to the pot and simmer over medium-low heat while stirring intermittently for about 10 minutes until thickened. Season with salt and pepper, to taste. Serve warm.