In a shallow dish, combine the gluten-free flour with salt and pepper. Dredge each chicken thigh in the seasoned flour, shaking off excess, and place on a plate.

In a medium-sized bowl, whisk together chicken broth, chopped pecans, pure maple syrup, Dijon mustard, apple cider vinegar, gluten-free Tamari, and dried rosemary. Set aside.

Heat extra virgin olive oil in a 12" cast iron skillet over medium-high heat. Once hot, add the chicken thighs and sear until golden brown on one side for 1-2 minutes. If needed, sear in batches to avoid overcrowding the skillet. Flip the chicken and sear until golden brown on the other side, then transfer back to the plate.

Remove the skillet from heat and carefully add the non-alcoholic bourbon substitute. It will boil immediately. Return the skillet to the heat and add the maple syrup mixture. Increase the heat to bring the liquid to a simmer, then reduce to medium heat. Nestle the chicken back into the skillet. Loosely cover the skillet with foil and simmer until the sauce reduces and the chicken is cooked through, about 10 minutes. Flip the thighs in the sauce once or twice.

Plate the chicken, spoon the sauce over the top, and serve.