Preheat oven to 350°F.

In a large cast-iron or oven safe pan over medium heat, heat canola oil and cook onions and lardons, stirring occasionally, until they begin to brown, about 5 minutes. Add cream and cook for 1 minute more.

Remove from heat and arrange potatoes on top in an even layer. Cover and bake until potatoes are tender, approximately 30 minutes.

Cut cheese in half horizontally, and place the half on top, rind side up, or sprinkle grated cheese over top, and bake until cheese is melted into the potatoes. Serve immediately.