At the Dilworthtown Inn, a colonial-style restaurant in West Chester, Pennsylvania, they serve their famous mushroom soup.
8 tablespoons (1 stick) butter, room temperature
2 cups sliced celery
1 cup sliced shallots
3/4 cup chopped onion
3 garlic cloves, minced
3 cups sliced stemmed fresh shiitake mushrooms (about 6 ounces)
3 cups sliced crimini mushrooms (about 6 ounces)
3 cups sliced oyster mushrooms (about 4 1/2 ounces)
1/2 cup dry white wine
1/2 cup dry Sherry
1/4 cup all purpose flour
8 cups chicken stock or canned low-salt chicken broth
1/2 cup whipping cream
Melt 6 tablespoons butter in large pot over medium-high heat. Add celery, shallots, onion and garlic and sauté until onion is translucent, about 8 minutes. Add all mushrooms and sauté until beginning to soften, about 4 minutes. Add white wine and Sherry. Boil until liquid is reduced to glaze, about 6 minutes.
Mix remaining 2 tablespoons butter and 1/4 cup flour in small bowl until smooth paste forms. Add flour paste to mushroom mixture in pot; stir until mixture melts and coats vegetables. Gradually mix in stock. Bring to boil, stirring frequently. Reduce heat to medium-low and simmer until mushrooms are tender, stirring often, about 10 minutes. Stir in cream. Season with salt and pepper.
Working in batches, puree soup in blender or processor until smooth. Return soup to pot.