Preheat the oven to 400 F.
Season the chicken with salt and pepper.
Place the bacon in a large Dutch oven or cast-iron skillet and cook over medium heat until the fat renders and the bacon is crispy, about 5 minutes.
Remove the bacon from the skillet and drain on a paper towel-lined plate. Wipe the skillet clean.
In the same pan, heat the olive oil over high heat. When the oil shimmers, add the chicken and sear until golden, 3 to 5 minutes per side.
Stir in the garlic and sage and cook until fragrant, about 1 minute more.
Scatter the potatoes around the chicken and add the wine, cream, mustard, and Parmesan. Season with salt and pepper.
Bring to a boil and reduce the heat to low. Sprinkle in the thyme leaves and crispy bacon.
Transfer the pan to the oven and roast until the chicken is cooked through and the potatoes are fork-tender, 25 to 30 minutes.
Garnish with the thyme sprigs and Parmesan and serve.
