Rinse the mushrooms and chop, if necessary. Peel and finely chop the shallot. Heat the oil in a large pot. Saute the shallot, half of the mushrooms and the dried mushrooms. Rinse the parsley, shake dry and add half to the pot. Pour in the water and simmer for about 15 minutes.
Peel and halve the garlic. Heat the butter. Saute the remaining mushrooms and garlic for about 5 minutes, until light brown.
Finely chop the remaining parsley. Pour the broth through a fine sieve. Season with salt and pepper. Bring the broth to a boil. Spread the garlic mushrooms in deep soup plates, pour in the hot broth and serve sprinkled with parsley.