This is a delicious woodland flavoring to use as an enhancement with cultivated mushrooms and with duck salads and as a basting liquid for lamb and pork.
Wash the cèpes under running water, rubbing them with your fingers to rid them of grit and dirt. Pat dry on paper towels.
When they are absolutely dry, place them in a jar. Tuck in the thyme and bay leaves and pour the olive oil over all. Let stand in a cool, dark place for at least 1 month.