To finish the lamb grill over direct heat. As the lamb finishes on indirect side, open the bottom vent all with way to start increasing heat. Once you transfer the lamb to the direct side, leave the lid open for a few minutes until the fire is robust. Ok to close the lid and grill for about 5 minutes each side, allowing the flames to return with an open lid each time your turn the lamb. For lamb we target an internal temp of 135 to 140.