Yes, you can freeze the blackened mahi mahi after it is completely cooked. Once it has cooled, wrap it tightly to store in the freezer for up to 3 months. When you are ready to use it, allow it to thaw completely in the refrigerator. Then, to reheat it, wrap it in foil and place in an oven set to 275 ° F/135 ° C for 15 minutes. The salsa and avocado cream do not freeze well. I recommend making them fresh each time you make this recipe.