Step 1

Place the dried mushrooms in a large bowl. Bring the broth to a boil and pour over the dried mushrooms. Set aside to rehydrate for about 20 minutes.

Step 2

Using a slotted spoon, remove the mushrooms and reserve the broth. Roughly chop the mushrooms.

Step 3

Heat the butter in a large pot over medium-high heat. Add the button and rehydrated mushrooms and cook, stirring occasionally, until soft and somewhat dry, about 6 minutes. Add the leek and shallot and cook, covered, stirring occasionally, until translucent, about 4 minutes. Stir in the flour and cook, stirring, for 2 minutes more.

Step 4

Pour in the reserved mushroom broth, taking care not to add any grit or dirt that may have fallen to the bottom of the boil, and bring to a boil while whisking constantly. Tie the parsley sprigs, fresh thyme, and bay leaf together with a piece of kitchen twine and add to the soup. Lower the heat and simmer for 10 minutes. Remove from the heat and allow to cool.

Step 5

Remove and discard the herb bundle. Working in batches, transfer the mixture to a blender and puree until smooth. Using a sieve over a large bowl, strain the mushroom puree. Return the puree to the pot and reheat over medium heat.

Step 6

Whisk the heavy cream, Madeira, and salt into the soup and season with pepper to taste. Divide among warm soup bowls and serve immediately.