Longwood Gardens is situated in Kennett Square, Pa., the mushroom capital of the world. So it's not surprising that the botanical attraction, founded by Pierre du Pont, would boast a rich, satisfying mushroom soup. Fortunately, the chefs at Longwood's Terrace Restaurant are happy to share the recipe.

Longwood Gardens Mushroom Soup

Ingredients:

1 teaspoon of vegetable oil

1 tablespoon of butter

1 leek, washed and diced

2 shallots, diced

3 stalks of celery, diced

1/4 cup of chopped thyme

1 cup of shitake mushroom caps, julienned

1 cup of crimini mushroom caps, quartered

1 cup of oyster mushrooms, julienned

1/ 2 cup of sherry wine

2 quarts of hot mushroom stock (see below)

1/2 cup of  heavy cream

1/4 cup of chopped tarragon

Truffle oil

Salt and pepper to taste

Saute the leek, shallot and celery in the oil and butter until leeks are translucent. Add thyme, salt and pepper. Add chopped mushrooms. Cook until mushrooms wilt and release their liquid. Add sherry wine and reduce by half. Add hot mushroom stock and bring to a boil. Simmer for 10 minutes. Add cream and tarragon. Let simmer for five minutes. Season to taste with salt and pepper. Finish with truffle oil

Mushroom Stock Recipe

Ingredients:

16 ounces of white button mushrooms, chopped

1 leek, chopped

1 onion, chopped

1 stalk of celery, diced

1 sprig of tarragon

1 sprig of thyme

1 1/2 gallons of water

Place ingredients in a tall saucepan. Add water, and bring to a boil. Simmer for an hour. Strain. Refrigerate leftovers.