Preheat oven to 450°F.
Rub chicken all over with the butter and salt. To make the marinade, place the remaining ingredients in a food processor and chop until a chunky consistency.
Place chicken breast-side down in a roasting pan and pour marinade over the top. Place pan in the oven.
After about 20 mins, turn the chicken breast-side up and spoon some of the marinade over the top.
After another 10 mins, turn oven down to 350°F. Baste again and continue to roast until a thermometer inserted into the thigh reads 165°F. Continue basting every 15 mins. Total cooking time shouldn't be much more than 1 hr, depending chicken size.
Remove chicken from the pan and let rest on a platter or carving board for 5 mins. Carve and enjoy.