1. Preheat the oven to 200°C (400°F).
In a pan, heat some oil and sauté your bacon, sliced button mushrooms, and chopped quenelles.
Add salt to the béchamel sauce, and add the cheese.
Arrange your vol-au-vent shells in an oven-safe dish and fill them with the mixture. Sprinkle grated cheese on top.
Bake in the oven for 15 minutes.