Coat the fish completely with kosher or rock salt and place in refrigerator for 12-14 hours (fish will become too salty to eat after 14 hours).
Rinse fish under cold water to remove the salt. Fish should now have a firm consistency. Combine the soy sauce, brown sugar, honey, and black pepper. Marinate the fish chunks for 24 to 36 hours.
Preheat the smoker to 160°F. Lightly grease the cooking racks with oil. Place the fish skin side down on the racks and cook for 1-2 hours. Check the fish every 30 minutes; it is done when flaky.