Begin by preparing the potatoes. If using larger potatoes, trim the tops and bottoms, peel them into a barrel shape, and halve them. For smaller potatoes, you can leave them whole. Leave them in the water.
In a frying pan, melt a tablespoon of butter or heat olive oil over medium-high heat. Add the diced bacon and fry until most of fat renders out (around 5 minutes).
Reduce the heat to medium and add the sliced shallots. Sauté until they're translucent, about 2-3 minutes. While doing this, preheat your oven to 180°C (356°F).
Place the onions and bacon evenly in a baking dish. Evenly distribute the fresh thyme leaves over them. Layer the potatoes on top, and position the quartered red onions and crushed garlic coves amongst the potatoes. Pour the stock and white wine over the mixture, ensuring the liquid comes up to just below the top of the potatoes.
Season the mixture with freshly ground black pepper. If you like, you can also add a pinch of salt, but be cautious as the bacon and stack already add saltiness.
Cover the pan with aluminum foil and transfer it to the preheated oven. Bake for 45 minutes.
After 45 minutes, remove the foil. If you wish, sprinkle some grated cheese over the top. Continue baking for another 15-20 minutes or until the potatoes are tender and have a golden-brown crust on top.
Once done, remove from the oven and let it rest for a few minutes. Garnish with freshly chopped parsley and serve with a dollop of crème fraiche.