1 refrigerated pie crust, or homemade pie crust for a single-crust pie
4 slices center-cut bacon
1 medium onion, diced
5 large eggs
2 Tbsp Greek yogurt, heavy cream or skim milk
1 cup grated Gruyere cheese
1/2 tsp kosher salt
1/2 tsp fresh black pepper
Preheat oven to 350°F.
Unroll one pie crust (for a 9-inch pie) and center it in a pie plate. Crimp the edges by hand, or press a design all around with a fork, or just bunch it down in a more rustic way. Set aside.
Stretch the bacon out in a cold nonstick frying pan. Turn the heat to medium, and cook until the bacon is brown but not crispy. Remove the bacon and drain on a paper towel lined plate.
Add the onions to the frying pan, and cook for 2-3 minutes, until the onions are completely wilted and just starting to brown. Remove from the pan and add to the bacon.
Let the bacon and onions cool for at least 10 minutes. (This step is important; if the filling is too hot, it will melt the pastry before the quiche gets to the oven.)
In a large measuring cup or bowl, whisk the eggs until they are smooth. Add the yogurt/cream/milk, and whisk again. Stir in the cheese, salt and pepper.
Crumble the bacon and scatter the bacon and onions in the pie crust. Pour the egg mixture evenly over the top.
Bake for 40 minutes. Let sit at room temperature for at least 10 minutes before serving. Serve warm or at room temperature.