Preheat oven to 375.  Carmelize onions on high heat until golden.  Add 1 cup water, mushrooms, bacon, garlic to onions and cook until all water is reduced. Set aside to cool.

In separate bowl, beat eggs then add heavy cream, cheese and onion/mushroom mixture.   Gently fold in spinach and pour mixture into the pie crusts.  Bake for 40-45 minutes until lightly golden on top and egg mixture has set.

This makes enough filling for 3 shallow pie crusts.