Slice mushrooms and spread them on a parchment or foil lined baking pan. Cup the top off of the garlic and wrap it in foil. Place next to mushrooms. Drizzle with olive oil. Bake in a 400 degree oven. Bake mushrooms for about 20 minutes. Take the garlic off of the roasting pan and bake for an additional 15 minutes. In a large pot, place butter and flour over medium heat until butter is melted and the two are mixed. Add roasted mushrooms. Take the roasted garlic and squeeze all of the garlic out of the skins and into the pot. Then add beef broth and thyme. Bring pot to a simmer. Add let the mixture thicken slightly.Add cream, and season with salt and pepper. Remove cooked thyme stems. Ladle soup into bowls and garnish with fresh parsley and more thyme.
