In a large pot, melt the butter over medium heat.
Add the sliced mushrooms, diced onion, and minced garlic. Sauté for 5-7 minutes until the mushrooms are tender and the onions are translucent.
Sprinkle the flour over the mushroom mixture and stir to coat. Cook for 2 minutes, stirring constantly.
Gradually whisk in the broth and bring to a simmer. Cook for 10 minutes, stirring occasionally, until the soup has thickened.
Stir in the heavy cream and season with salt and pepper to taste.
Serve hot and enjoy!
