Using a tablespoon of butter, butter 12 four-ounce timbales and chill.
Preheat oven to 425 degrees.
Melt a tablespoon of butter in a small frying pan and saute the shallots until soft.
Add the mushrooms and cook for one minute.
In a blender puree the mushroom-shallots mixture and remaining ingredients except cream and eggs.
Scald the cream and add in a slow, steady stream to the ingredients, blending at medium speed.
When the mixture is smooth add the eggs.
Place in a blender and blend at high speed for 10 seconds.
Turn off and let rest for two minutes.
Pour the mixture evenly into the timbales and put the timbales into a bain marie, a large pan containing an inch of hot water.
Cover with buttered parchment and cook for 5 to 10 minutes or until the point of a sharp knife comes out clean or until the mousse feels firm to the touch.