Preheat the oven to 180°C (350°F).

Pat the chicken thighs and legs dry with paper towels and season them generously with salt. In a large, oven-safe skillet, heat olive oil over medium-high heat. Once the oil is shimmering, carefully add the chicken skin-side down and brown for 5-7 minutes until golden and crispy. Set aside.

In the same skillet, cook the bacon lardons for 4-5 minutes until crispy and golden. Remove from the pan and set aside, leaving the bacon fat behind.

Using the reserved bacon fat, sauté the shallots and celery for 5-7 minutes until softened and translucent.

Stir in the minced garlic and fresh thyme, cooking for an additional 30 seconds until fragrant.

Pour in the brandy or whiskey, scraping the bottom of the skillet to incorporate any flavorful bits. Allow to simmer for 1-2 minutes until mostly evaporated.

Sprinkle in the flour, stirring continuously to form a roux. Gradually whisk in the chicken stock and apple cider, cooking until the sauce thickens, about 2-3 minutes.

Return the browned chicken and crispy bacon to the skillet, nestling them into the sauce. Cover and transfer to the preheated oven. Bake for 30 minutes.

Remove the lid to allow the chicken to crisp up. Bake for another 30 minutes until the skin is golden brown.

Meanwhile, heat a small pan and fry the apple wedges in the remaining bacon fat until golden and tender. Fold them into the casserole before serving.