Quiche Lorraine

Preheat the oven to 425 degrees F (220 degrees C).

Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain bacon slices on paper towels, then chop coarsely.

Sprinkle bacon, Swiss cheese, and onion into prepared pastry crust.

Whisk cream, eggs, salt, sugar, and cayenne pepper in a medium bowl; pour mixture into pastry shell.

Bake in the preheated oven for 15 minutes. Reduce heat to 300 degrees F (150 degrees C) and continue baking until a knife inserted 1 inch from the edge comes out clean, about 30 minutes.

Allow quiche to sit 10 minutes before cutting into wedges and serving.