• Pre-heat oven to 350ºF.

Cook Mushrooms:

• Prepare mushrooms by tearing into small pieces. (Alternatively, slice them.) If using mushrooms with a tough stem (like shiitake or king oyster), discard and compost the stem.

  Heat a large pan over medium heat. Add the butter and oil. The butter will begin to foam as it melts. When it stops foaming, add the mushrooms in a single layer.

  Don't crowd the mushrooms or they will steam instead of browning. If you have too many mushrooms to fit in a single layer, work in batches.
  
• Toss the mushrooms frequently to make sure they cook evenly.

  When the mushrooms are lightly toasted, add the chives (or green onions) and garlic. Toss and cook for about another minute, until the garlic is fragrant.

  Off-heat, add the salt and toss again.
  

Blind Bake Pie Dough:

• Arrange pie dough inside a pie pan.  Prick the bottom and sides with a fork.  Set parchment paper on top of dough, and add pie weights or dry beans.  Bake 10 minutes.  Remove weights and parchment paper.

  Tip: Pre-made, pre-formed, frozen pie dough will not need pie weights added while blind baking.
  

Make the Quiche:

• Add the mushrooms to the pie dough and add half the cheese.
  
• Add 3 eggs, milk, and cream to a mixing bowl.  Use an electric hand mixer to whip the mixture until it doubles in size.  (Alternatively, whisk vigorously by hand.)

  Add the remaining cheese to the egg and milk mixture, and gently fold in with a spoon.  Take care not to over-stir. 

  Pour the egg mixture into the pie pan.  

  Tip: Do not overfill the quiche-- any extra mixture can be discarded, saved for another quiche, or used to dip bread in for French toast.
  
• Tent quiche loosely with aluminum foil.  Bake 45 minutes.  Remove foil, and bake 15-20 more minutes until the quiche is golden and set.  Quiche should jiggle slightly when moved.
  
• Allow quiche to cool for at least 1 hour, or refrigerate overnight.  (Quiche will not be fully set until cooled.)

  While quiche cools, stir together all the sauce ingredients (if using).

  Serve quiche cool, or slightly warmed.
• Leftovers / Make Ahead + Refrigerate:

  Refrigerate and use within 2-3 days.

  Make Ahead + Freeze: 

  Bake quiche, and allow to cool completely.  Wrap tightly with plastic wrap, and slide into a freezer bag.  Use within 2 months.

  Reheat from Frozen: Do not thaw.  Bake at 350ºF for 20-25 minutes, or until pie is warm.

  Tip: If freezing, bake quiche in either a disposable aluminum pie pan or in a tart pan with removable sides.  (Allow quiche to fully cool before removing the pan.)

  Sauce should not be frozen, but can be refrigerated for up to a week.