Prep: Heat the oil or butter in a skillet over medium heat. Add the mustard to a medium mixing bowl and set aside. Finely chop the walnuts if necessary and add to a second mixing bowl; then add the spices, salt and pepper and mix to incorporate with the walnuts.
Coat: Add the chicken thighs to the bowl with the Dijon mustard and use your hands to mix and coat all surfaces of the chicken. One by one, dip and coat each thigh in the walnut and spice mixture and place in the skillet smooth side down.
Cook: Cook the chicken in the oil for 4-5 minutes until browned on the underside. (Don't peek earlier than that, for best results.) Flip each thigh over, reduce the heat to medium low, and cover. Cook for another 5-7 minutes or until the juices run clear using either a fork or sharp knife to test. If necessary, flip once more to cook through.
Enjoy: Serve immediately and top with any remaining walnuts in the skillet. Enjoy!
Notes
Storage: Pan fried chicken will stay fresh in an airtight container in the fridge for up to 4 days, or in the freezer for up to 2 months.