On a small dish, we mixed the sage, lemon, garlic, salt and pepper. We then put that mixture under the skin of the breast and the thigh.
We turned on our gas grill, with half of the grill on medium, the other off to prevent it from getting too hot and drying out the chicken. After the grill had a chance to warm up (and burn off some built-up grease), we put the chicken on the heated side with the skin side up. On top of that, we put our brick (wrapped in heavy duty aluminum foil). The grill cover was closed and the chicken cooked for 15 minutes.
Using a potholder, lift grill cover and remove brick. Flip chicken over with tongs, replace brick, and put the grill cover down again. After another 15 minutes check chicken. We want the juices to run clear and the temperature in the leg-thigh joint to be 180 degrees F. Pull chicken off to a plate and squeeze half a lemon onto skin side. Return chicken to the turned-off section of the grill for a few minutes while you get the marinated vegetables onto the grill. Remove chicken from grill and let rest for at least 5 minutes.