Pre-heat oven to 375 degrees F
You will need a dutch oven or high sided fry pan
Butter or oil dutch oven/pan set aside
Add the dijon mustard, salt, pepper to the melted butter. Stir to combine, mixture will thicken.
Starting with the breast side, gently lift the chicken skin being careful not to break it, next put about 1 tbsp of mustard mixture under the skin on each side, massaging it around to cover as much as possible.
Flip the chicken and repeat on the back side.
Using whats on your hands massage the mustard mixture on top of the skin on the back side.
Salt and pepper the top of the back side of chicken.
Place chicken into prepared pan breast side down.
Save remaining 1 Tbsp mixture for when you flip the chicken to rub on top of skin on the breast side.
Bake chicken for 45 minutes.
After 45 minutes flip the chicken over, careful that the underside skin is not sticking to the pan.*
The breast side should now be facing up and you can rub remaining mustard mixture on top, salt and pepper the chicken again and roast for another 45 minutes or until juice run clear.**
Allow to rest for 10 minutes. Cut and serve.