The night before my brother's wedding his wife-to-be's parents took us out to dinner. We were in Detroit and my expectations weren't high, but I had an extraordinary mushroom bisque that I set out to recreate when I got home. It took several years to achieve something as good as I remembered. —Kevin
Bring sherry to a simmer over medium heat. Remove from heat, add dried mushrooms, and rehydrate for 30 minutes. Remove mushrooms to a small bowl with a slotted spoon and strain sherry through a coffee filter or cheese cloth and reserve. Note: Half the mushroom flavor comes from this broth.
Place a soup pot over medium high heat and add half of the mushrooms (Note, do not oil the pan.) Sprinkle generously with salt and cook, stirring occasionally to prevent burning, until the mushroom have reduced by half. Add remaining mushrooms, sprinkle with salt, and add thyme and shallots. Continue cooking until the volume is again reduced to half.
Add butter and toss with mushrooms to melt. Add sherry and reduce to a syrup. Add rehydrated mushrooms and stock. Bring to a vigorous simmer, then reduce heat and continue to simmer for 15 minutes. Add half and half. Puree soup using either an immersion blender or standing blender. Return to heat and warm thoroughly.
Serve with a light splash of sherry (don’t stir it in) and with a dollop of sour cream or crèam fraîche.