In a medium bowl, combine peach preserves, bourbon, olive oil, soy sauce, apple cider vinegar, Dijon mustard, garlic, salt, black pepper, and red pepper flakes. Set aside half of the mixture (about ¾ cup) and refrigerate for later use.
Place the salmon fillets in a resealable plastic bag and pour in the remaining half of the marinade. Seal the bag and mix well to coat the salmon. Refrigerate for at least 30 minutes, up to 1 hour.
Preheat the oven to 375°F.
In a medium, oven-safe skillet over medium-high heat, add oil. Once hot, place the marinated salmon fillets in the skillet, skin side up. Cook for about 2-3 minutes or until seared and golden brown.
Flip the salmon fillets to skin side down. Add the sliced peaches to the skillet. Cook for 2-3 more minutes, allowing the peaches to soften and the salmon skin to sear slightly.
Remove skillet from heat. Pour the reserved peach marinade into the skillet, evenly distributing over the salmon and peaches.
Transfer the skillet to the preheated oven and bake for 12-15 minutes (check at 12 minutes) until salmon is cooked through, reaching an internal temperature of 145°F.
Once cooked, remove from the oven and serve the roasted peach and salmon dish immediately.