Preheat oven to 375° F.
Beat the eggs, cream, grated cheese, and pepper until
thoroughly mixed.
Cook the onions in butter in fry pan until they are just
beginning to turn translucent. Add mushrooms and lemon juice. Cook
over moderate heat until mushrooms give up their liquid. Then
turn up heat and boil until liquid is completely evaporated and mushrooms
are beginning to sauté in their butter. Turn off heat and let rest off
burner for a minute or so until mushrooms cool a bit.
Spoon mushrooms and their butter into pastry shells.
Pour cream, egg and cheese mixture over mushrooms until shells are filled.
Place shells (on the baking sheet*) into the oven and bake 25± minutes
until top is a light brown and quiche is a bit puffy. Do not overcook
or quiche will be unpleasantly dry.
Remove from oven and let rest 5-10 minutes.
* The importance of the baking sheets will become
apparent when you try to place the quiche into the oven. It is
almost impossible to do so without spilling some of the liquid.
Without the baking sheet -- what a mess, as the liquid spatters all over
the hot oven door and floor.