Prepare the chicken by patting it dry with paper towels and seasoning generously with salt and pepper.
In a shallow dish, mix together 1/2 cup of gluten-free flour with additional salt and pepper.
Dredge each chicken thigh in the seasoned flour, shaking off the excess, and place them on a plate.
Heat olive oil in a cast iron skillet over medium-high heat until shimmering.
Once hot, add the chicken thighs skin-side down and sear for 4-5 minutes until golden brown, then flip.
Sear the other side until golden brown, about another 4-5 minutes, then transfer to a plate.
Remove the skillet from heat and add 1/4 cup bourbon carefully, returning to the heat once added.
Add 1/2 cup of maple syrup, mustard, apple cider vinegar, and rosemary to the skillet, stirring to combine.
Bring the sauce to a simmer and nestle the chicken back into the skillet.
Cover loosely with foil and simmer for 10-15 minutes, flipping the chicken halfway through.
Once cooked through, plate the chicken and spoon the sauce and pecans over the top.