I used a cast iron pan on the grill to cook blacked grouper and royal reds shrimp. I used Fiesty Fish Rub and Swamp Venom with olive oil on the shrimp. I used Dizzy Pig Raging River Rub and olive oil on the grouper. I cooked the fish at 500 for 3 minutes one side and two minutes the other using butter on the pan. The shrimp was cooked for 2 minutes and then 1 minute. After that time I removed the pan to keep it hot and finish cooking the second side. While the fish finished I cookd the zucchini and yellow squash for about 2 minutes a side directly on the grill. This was the first time I tried blackened fish and it will not be the last time. It turned out great.