Preheat oven to 375°F (190°C).

Cook bacon in a skillet until crisp.

Remove bacon from skillet and crumble. Reserve 1 tablespoon of bacon fat in the skillet.

Add chopped onion to the skillet with the bacon fat and cook until tender and translucent.

In the unbaked pie shell, layer the crumbled bacon, cooked onion, grated Swiss cheese, and Parmesan cheese.

In a separate bowl, whisk together the eggs, light cream, salt, and pepper.

Pour the egg mixture evenly over the bacon, onion, and cheese in the pie shell.

Bake in the preheated oven for approximately 45 minutes, or until the filling is firm and lightly golden brown.