Line the empty pie shell with parchment and fill with pie beads. Par bake in the preheated oven for 15 minutes.
While the pie shell is baking, prep the add-in ingredients. Cook and chop the bacon, shred the cheese, and dice the scallion.
Remove the pie shell from the oven. Carefully remove the parchment and pie beads. Fork holes into the bottom of the pie shell and return to the oven for another 5-7 minutes.
Combine the eggs, milk, salt, and pepper in a large bowl with a spout for easy pouring. Add in the bacon, cheese, and scallions being careful not to overfill.
Bake in the oven for 45-60 minutes, until center is almost set.
Remove from the oven and cool for 15 minutes before serving, or cool completely and cover to refrigerate for later.