Preheat oven to 400° degrees Fahrenheit.
Arrange halibut fillets on foil-lined sheet pan.
Spread1 tablespoon of mayonnaise, followed by sprinkling 1/4 teaspoon of salt, over each fillet.
Sprinkle 1/4 tsp. of salt over each Halibut Steak.
Grind croutons in food processor until coarse.
Mix ground croutons with chopped parsley.
Top each filet with 1/2 cup of ground up garlic-herb croutons.
Pack breading and dredge fillets through it to thoroughly coat each fillet.
Roast until breading is browned and fillets are opaque in color and have reached an internal temperature of 145 degrees Fahrenheit.
Squeeze a lemon wedge over each fillet and garnish with a parsley sprig before serving with a side of tartar sauce.