Fully baked and cooled tart shell baked in a 10-inch ceramic quiche dish, deep 10-inch tart pan, or 10-inch pie pan
5 large eggs
3 tablespoons flour
1 cup creme fraiche
1 cup whole milk
1 teaspoon salt
1/2 teaspoon freshly ground black pepper
1 tablespoon fresh thyme, finely chopped
Have the pie shell ready for filling. Preheat the oven to 375.
Put 1 egg and the flour in the bowl of a stand mixer or a large mixing bowl and mix at high speed or by hand with a whisk until smooth (I used a handheld mixer in a large bowl). Mix or whisk in the remaining 4 eggs until blended. In a medium bowl, whisk the creme fraiche until it is perfectly smooth and then whisk in the milk.
Pour the egg mixture through a fine-mesh sieve held over the milk mixture. Whisk in the salt, pepper, and thyme. (You can prepare the custard up to 4 days in advance before baking; cover and refrigerate. The flour, thyme, and pepper will settle to the bottom of the storage container and might stick to it, so whisk well before using.)
Pour the egg mixture into the pastry shell. Put in the oven and bake for 10 minutes. Reduce the oven temperature to 325? and bake until the filling is just set, about 30 minutes longer (for me it was 40 minutes). When touched, the center of the quiche should feel slightly firm, not liquidy. Let cool on a wire rack for at least 20 minutes to allow the custard to set up, so that it will slice neatly. Serve warm or at room temperature. To reheat a fully cooled quiche, cover with foil and bake at 325 for about 15 minutes.