Marinate the fish in the spices and oil (1 1/2 tablespoons Cajun seasoning like Old Bay Seasoning, 1 teaspoon each of black pepper powder and cayenne pepper powder and 1 tablespoon of cooking oil). Set aside for at least 15 minutes. In a hot pan on high heat, add a tablespoon of olive oil and add 1 cup of roughly cut bell peppers in. Sauté the peppers until lightly charred.
Add 1/2 cup chopped spring onions, 1 tablespoon finely chopped garlic and 2 tablespoons butter and sauté until the butter starts foaming. This should take about a minute.
As soon as the butter starts foaming, add 2 cups cooked and roughly cut sweet potato. You can precook the sweet potato by boiling it or oven roasting it.Add in the salt and pepper and toss. Sauté while stirring continuously for a minute. Add the juice of half an orange and sauté for another 30 seconds.
Turn off the flame. Add some chopped fresh parsley and mix through to finish.
Brush 1 tablespoon of cooking oil (any variety) onto a non stick pan.
Turn the flame on medium heat and cook the marinated fish, repeatedly flipping over in the pan. Cook for about 2 - 3 minutes or until desired doneness and the surface takes on the characteristic blackened colour.
Serve with the hash and a squeeze of lime.