In a resealable plastic bag mix the salt, pepper, Cajun seasoning,and flour. Place the fish in the bag, seal and shake to lightly coat.
Heat the oil and melt the butter in a frypan over medium heat. Place the fish in the frypan and cook for about 3 minutes. Mix in the garlic, tomato and mushrooms and continue cooking 3 minutes. Mix in the wine and parsley. Continue to cook and stir 2 minutes, or until the fish flakes easily with a fork.