Add lemon juice, dijon mustard and olive oil to a bowl with seasonings and mix thoroughly
Add chicken thighs to the bowl and coat with the marinade
Cover the bowl and place in the refrigerator to chill and marinate for at least 4 hours
When you are ready to grill, preheat your grill or grill pan to medium-high
Remove the chicken thighs from the marinade and allow excess marinade to drip off to avoid flames in the grill
Add the chicken thighs to hot grill or grill pan
Cook for about 4 minutes on each side on grill, 6 minutes each side on grill pan - you may need shorter or longer depending on the heat of your grill or stove - the best way to ensure your chicken is cooked through but still moist is to use a meat thermometer and check for an internal temperature of 165F
Allow the chicken thighs to cool slightly and then slice and enjoy!