Prep. Preheat the oven to 350 F, and prep your pie crust. If prebaking (not necessary with my recipe), allow it to cool completely before adding the filling. Place prepared pie crust on a rimmed baking sheet before filling.
Bacon. Cook bacon (7 slices) in a medium skillet until crispy, about 8 to 10 minutes. Place cooked bacon on a paper towel-lined plate.
Saute. Add onions (1/2 chopped) and chopped leeks (1/2 cup), and saute in the bacon fat (note 4) until softened, about 5-7 minutes. Sprinkle bacon, onions, and leeks along the bottom of your pie crust, followed by half the cheese.
Combine. In a medium bowl, whisk eggs (6). Add heavy cream (1 cup), salt (1/2 teaspoon), a dash of white pepper, nutmeg (1/8 teaspoon), fresh thyme (1 teaspoon), and combine. Pour into the pie crust, and sprinkle the remaining cheese on top.
Bake for 30-35 minutes, you'll know the quiche is done once it has set completely in the center. Allow quiche to cool slightly before serving.