30 large (or 1 cup) garlic cloves (peeled)
2 cups heavy cream
  Salt and freshly ground pepper (to taste)
1 8-ounce frozen puff pastry sheet (defrosted 20 minutes, at room temperature)
2 tablespoons extra-virgin olive oil
1 1/2 pounds fresh medium-size shiitake mushrooms (stems removed)
  Salt and freshly ground pepper (to taste)
6 fresh herb sprigs (like parsley or chervil, optional)