In your large pot or Dutch oven, heat a drizzle of olive oil over medium heat. Add the finely chopped garlic and shallots. Sauté them for about 3-4 minutes until they become translucent and fragrant.
Add the button and cremini mushrooms, stirring well to combine. Cook for about 8-10 minutes until the mushrooms are soft and have released their moisture.
Add the truffle oil, fresh thyme, salt, and pepper. Stir everything together and let it cook for another 2-3 minutes.
Pour in the chicken broth and bring the mixture to a gentle simmer, allowing it to cook for about 15-20 minutes.
Remove from heat and blend the soup until smooth and creamy using an immersion blender.
Return the blended soup to the pot and stir in the heavy cream and lemon juice. Heat on low for a few minutes.
Ladle the soup into bowls and finish with a drizzle of truffle oil and a sprinkle of croutons. Enjoy!
