Wild Mushroom Soup

1½ pounds mushrooms, trimmed and cut into similar size pieces (use a variety of your favorites) 
2 tablespoons olive oil
1 tablespoon butter
2 tablespoons shallots
1 tablespoon minced garlic
¼ cup dry sherry (not vinegar)
2 tablespoons soy sauce 
6 cups chicken stock
1 cup warmed half-and-half
2 sprigs thyme, leaves removed
3 sprigs tarragon, leaves removed 
1 bunch chives, sliced thin (for garnish)

In a medium-size pot, over medium heat, melt the butter in the oil.  Add the shallots, garlic and mushrooms; cook stirring until the mushrooms are soft and the liquid evaporates.  Add the stock, allow it to come to a boil, reduce to a simmer and add the sherry and soy sauce.  Allow to cook for 20 minutes, add the warm half and half, herbs and puree until smooth in a blender. Top with chives.