In a bowl, combine all the ingredients. Generously season with pepper and stir well to combine. Set aside.
Preheat the grill, setting the burners to high. Oil the grate.
On a work surface, gently lift the skin from the meat beginning from the cut side of the thigh to create a pocket. Avoid tearing the skin. Spread the herb butter between the meat and skin of each leg. Season with salt.
Reduce the burners to medium-low. Place the chicken
on the grill, skin side up. Close the lid and cook for 25 to
30 minutes, or until the meat pulls easily from the bone.
If using a thermometer, the temperature should read 180°F (82°C) when it is inserted in the centre of the meat (without touching the bone).
If desired, serve with the Spring Bean and Arugula Salad (see recipe).