You may soak the king mackerel in milk for 1 hour prior to making the cakes, but you may omit this step. Milk may help to take the strong flavor out.
Pour the milk off if you soaked it. With a spoon scrape the fish from the connective tissue and chop any large chunks into smaller random pieces (about the size of mixed nuts).
Finely chop the onion, celery, and bell pepper.
Add the remaining flour mixed with 1 tablespoon creole seasoning in a shallow dish for breading. Set aside.
In a large bowl, combine the fish, onion, celery, bellpepper, garlic powder, worcestershire sauce, and eggs, hot sauce and 1/2 tablespoon creole seasoning. Mix together (works best with your hands). Add the bread crumbs and about 1/4 cup flour.
Form the mixture into large meatball sized handfuls. Flatten to about 1/2 inch. Add more flour/breadcrumbs if mixture is too wet and won't stick together. Mixture may crumble slightly but should hold together. Pat both sides of cake in flour mixture that was set aside.
In a large frying pan add a couple of tablespoons of canola oil and a tablespoon of butter and heat over medium heat. Fry cakes until browned on both sides. Transfer to a dish lined with paper towels and keep warm in an oven until you are ready to serve.