Heat the oil in a frying pan. Add the
shallots and garlic, and gently sauté for
a couple of mins. Remove the porcini
mushrooms from the soaking liquid and
squeeze out any excess. Roughly chop
and add to the pan along with the
chestnut mushrooms and thyme. Cook
for about 5 mins. If the mixture seems
dry, add a little mushroom soaking liquid.
Remove from the heat and stir in the
mascarpone and Parmesan. Season and
leave to cool. Chill until ready to use.
Divide between 10 vol-au-vent cases
and serve scattered with Parmesan
shavings and a few thyme leaves.