Take my word for it, the sauce is what makes all the difference here.

Preheat your oven to 375°F (190°C).

Place the pie crust in a 9-inch round quiche or pie pan and set aside.

In a skillet, heat olive oil over medium heat. Add the sliced leeks and cook until they are soft and translucent, about 5 minutes.

Layer the potato slices evenly over the pie crust, followed by the cooked leeks and crumbled bacon.

In a mixing bowl, whisk together the eggs, heavy cream, and half of the shredded Gruyère cheese. Season with salt and pepper.

Pour the egg mixture over the layered ingredients in the pie crust.

Sprinkle the remaining Gruyère cheese on top.

Bake in the preheated oven for 35-40 minutes, or until the quiche is set and the top is golden brown.

Allow the quiche to cool on a wire rack for a few minutes before slicing and serving.

For a vegetarian version, omit the bacon and add sautéed mushrooms or spinach for added flavor and texture. You can also experiment with different cheeses, such as cheddar or feta, to change the flavor profile. For a gluten-free option, use a gluten-free pie crust or make a crustless quiche by simply baking the filling in a greased pan. To add a bit of spice, consider incorporating a pinch of red pepper flakes or a dash of hot sauce into the egg mixture.