Peel, dice, and boil the potatoes until just tender.
While the potatoes cool, dice the slab bacon and cook it in a pan until crispy.
Add sliced onions and white wine to the pan, sautéing in the bacon fat.
Drain the potatoes, season with salt and pepper, and toss with the bacon mixture.
In a casserole dish, layer half the potato mixture, top with slices of Brie cheese, add another layer of potatoes and lardons, and finish with more cheese.
Bake in a 350°F oven for 20 minutes until the cheese is golden and bubbly.
