Heat the olive oil in a large soup pot over medium heat. When the oil shimmers, add the shallots and garlic, cook until fragrant, about 2-3 minutes. Add the mushrooms, and season with salt and pepper. Cook undisturbed for 5 minutes or until golden, stir and continue cooking until the mushrooms have caramelized, 3-5 minutes. Reduce the heat to medium. Add the butter, sage, and thyme. Cook, stirring occasionally, until very fragrant, about 2-3 minutes. Stir in the balsamic vinegar. Spoon out a handful of the mushrooms for topping, if desired. Add the 4 cups broth, season with salt and pepper. Transfer about 3/4's of the soup to a blender and pulse until smooth and creamy. Return the soup to the pot with the remaining soup. Stir in the cream and cheese. Season the soup with salt and pepper. Simmer the soup for 5-10 minutes until warmed through, adding the addition 1-2 cups broth as need to thin the soup.Meanwhile, make the bread. Preheat the oven to 425 degrees F. On a baking sheet, toss together the bread, olive oil, oregano, thyme, garlic, and a pinch of salt. Transfer to the oven and bake for 10-15 minutes or until toasted. Ladle the soup into bowls. Top with garlic herb bread and reserved mushrooms.