Preheat the oven to 350 degrees F.
In a large cast iron dutch oven (or another dutch oven that is both stovetop and oven safe), heat the olive oil over medium heat.
Season the chicken with salt and pepper, and sear each side in the hot oil for 2-3 minutes per side, working in batches. Remove the chicken and set aside on a plate for now.
Add the onion to the pot and sauté for 3-4 minutes, until it starts to get translucent. Add the peaches and cook for another minute.
Add the whisky to the pot and cook for 2-3 minutes, letting some of the liquid evaporate off.
Stir in the BBQ sauce and fruit preserves, then add the chicken back to the dutch oven. Spoon sauce over the chicken. Place the lid on the dutch oven and place in the preheated oven. Cook for about 60 minutes, or until the chicken is cooked through (reaching an internal temperature of 165 degrees).
Optional but recommended: Let the pot sit out uncovered for about 15-30 minutes before serving to thicken up the sauce. Enjoy!