Combine a dry rub mixture consisting of one-cup salt, ¼ cup of brown sugar, 1 teaspoon of sage and 1 teaspoon of thyme. Rub the fresh or thawed turkey inside and out with mixture. Place in a bag and refrigerate overnight.
Prepare the fire: Soak hardwood chunks in water for 1 to 2 hours. Open bottom dampers of the Portable Kitchen® cooker. Remove cooking grid. Place 25 to 30 briquettes on the charcoal grate over the damper at the oven’s hinged end. Light and burn briquettes until covered with gray ash, about 30 minutes. Add wood chunks. Replace the cooking grid with movable half over the fire.
Rinse turkey and pat dry with paper toweling. Place bird breast down, in a pan with a stick of butter in the cavity. Place pan opposite the fire (end with oven handle). Close the lid and open the vent over the turkey 1/3. The opposite bottom damper, directly under the fire, should be open 1/3. The other vent and damper should be closed. Add briquettes and wood chunks every two hours. Maintain a temperature of 225º F to 250º F (use oven safe thermometer).
Cook turkey to internal temperature of 180º F in the thigh and 170º F in the breast. Also, the drumstick should move easily in the socket. Turkey may take up to anywhere from 8-12 hours depending on the size and weather conditions. Let the turkey stand 15-20 minutes before carving.