Place Porcini in medium bowl. Pour boiling water over. Let stand until softened, about 30 minutes. Drain, reserving soaking liquid. Strain soaking liquid through cheesecloth to remove any dirt. Coarsely chop Porcini.
Melt butter in heavy large saucepan over medium high heat. Add onion and saute until tender, about 5 minutes. Add garlic, Shiitake and Porcini and saute until mushrooms are tender, about 5 minutes. Add Sherry and boil until almost all liquid evaporates. Add reserved soaking liquid and stock. Simmer soup 15 minutes to blend flavors. Add Enoki mushrooms and stir until heated through. Season to taste with salt and pepper. Ladle soup into bowls. Drizzle with additional Sherry and garnish with epazote, oregano or chives.
c.1997, M.S. Milliken & S. Feniger, all rights reserved