Step 1

Preheat the oven to 375°F with a baking sheet on the center rack. Fit the pie crust into a 9-inch pie plate (not deep dish). Fold the edges of the crust under and crimp as you like. Chill in the refrigerator while preparing the filling.

Step 2

Cook the bacon in a large nonstick skillet over medium heat, turning occasionally, until crisp, 10 to 12 minutes. Transfer the bacon to a paper towel-lined plate and set aside.

Step 3

Reserve 1 tablespoon of the bacon drippings in the skillet and heat over medium-low heat. Add the onion, thyme, and 1/2 teaspoon of salt. Cook, stirring occasionally, until the onions are soft and golden, 12 to 15 minutes. Remove from the heat and let cool for 10 minutes.

Step 4

In a large bowl, whisk together the eggs, half-and-half, chives, flour, pepper, and remaining 1/2 teaspoon salt. Crumble the bacon into about 3/4-inch pieces and reserve 1/4 cup for topping.

Step 5

Sprinkle the onion, remaining bacon, 3/4 cup of Swiss cheese, and parmesan cheese in the bottom of the chilled pie crust. Pour in the egg mixture.

Step 6

Place the quiche on the pre-heated baking sheet and bake for 15 minutes. Sprinkle the remaining 1/4 cup Swiss cheese and remaining 1/4 cup reserved bacon over top. Continue to bake until puffed in the center, just set, and starting to brown, 15 to 20 minutes more. Transfer the quiche to a wire rack to cool for at least 30 minutes before serving. Top with more fresh chives, if you like.