Peel potatoes and place in a pot of cold water.

Bring to a boil over high heat and cook until potatoes are easily pierced with a fork (about 20 minutes).

Drain the potatoes well and cover with a clean dish towel for 10 minutes to remove excess moisture.

Preheat oven to 400 degrees F (200 degrees C).

Heat vegetable oil in a large skillet over medium heat.

Cook bacon until very crispy (5 to 8 minutes).

Drain bacon on paper towels.

Transfer bacon to a blender and blend into tiny pieces.

Break Camembert cheese into small lumps.

Mix Camembert cheese with Cheddar cheese and thinly sliced spring onion in a bowl.

Mash potatoes until smooth.

Stir in bacon, Camembert cheese mixture, half of the light cream, and butter into the mashed potatoes.

Season with salt and pepper to taste.

Spread mashed potato mixture in a baking dish.

Pour remaining light cream on top.

Pierce the top of the mixture in several places with a fork.

Bake in the preheated oven until the top starts to brown (about 15 minutes).