Melt butter in a large soup pot over medium-high heat, add mushrooms and onions, and cook until tender, 10-15 minutes, stirring frequently. Set aside a few mushroom pieces for garnish, if desired.
Stir in vegetable broth, thyme and salt and pepper.
Transfer soup in batches to a food processor or blender, and puree until soup is smooth.
Return soup to pot, and stir in cream. Whisk in LC-Thick n’Saucy and heat through.
Serve in bowls, garnished with reserved mushrooms and/or sprinkle with some additional dried thyme
