Clean and slice your mushrooms into 1/8" slices. Melt butter in a large dutch oven over med heat. Add the onion, garlic and rosemary and saute until soft, about 5-8 minutes. Turn the heat to medium high and add the mushrooms with a bit of salt and saute until they give off their liquid and get soft, about 20 minutes.Add the sherry and water and continue to simmer for another 10 minutes or so until the flavors blend together. Using an immersion blender blend the soup to a smooth consistency. If you don't have an immersion blender, use a regular one but let the soup cool for a few minutes before you blend and make sure to keep the lid on the blender. Once the soup has been blended to your desired consistency return to the pot and add the cream along with salt and pepper to taste.
Stuffing Crouton
While the mushrooms are cooking get started on the stuffing. In a small skillet melt the butter over med high heat and add the mushrooms and shallot along with the rosemary and sage and saute until they become soft. Add the stuffing mix and just enough chicken broth to moisten it up. Somewhere between and 1/4 and 1/2 cup should do it. Spray a muffin time with cooking spray and fill with the stuffing. Bake 400 degrees for 20 minutes until golden brown and crunchy.