Put the flour, seasoning salt, pepper, onion and garlic powder together in a large resealable bag. Shake together and add the fillets; shake again to cover. In a small bowl, mix the mayonnaise and mustard together; set aside.
Heat a heavy skillet and oil to medium. Toss in a little bit of the flour mixture to see if it cooks it. When it does, it's ready to go. Keep the oil handy as you will have to add a little throughout the cooking process.
Delicately add a few fillets (do not overcrowd) to the hot oil. When it starts to turn golden brown; flip. Lightly spread a little bit of mayo/mustard mixture over the brown side. Cook until the other side is turning golden; carefully flip again. We are going to flip this a few more times as you continue to baste. If you run out of mixture, just make more.
Continue to base browned sides of fillets until they reach a deep brown color. Test them with a fork to see if they flake; if they do, they are done.
If you have to cook more, just place these fillets in a pan tightly covered with foil and leave in a 200 degree oven. You must cover them tightly or they will dry out.
Serve with lemon wedge, steamed vegetables (broccoli, carrot, peas) and boiled potatoes.
Get more halibut recipes from Miss Homemade here.
How about strawberry pretzel dessert? It's delicious and a wonderful way to have dessert and not feel so guilty because the fish meal was healthier. Enjoy.