In a shallow bowl, combine flour and baking powder. Whisk egg and mustard together in a second shallow bowl. In a third shallow bowl, season breadcrumbs with garlic powder, salt, pepper, paprika, and Italian seasoning. Dredge fish in flour, then egg, then breadcrumbs.
Heat oil in a skillet and fry fish until crispy on both sides.
In a small bowl, whisk together all the slaw dressing ingredients. Mix with the cabbage and let sit 10 minutes.
In a medium bowl, combine tomato, scallion, olive oil, salt, and pepper.
Warm up the tacos in oven, or place it directly over an open flame for 30 seconds on each side.
To assemble the tacos, fill each taco wrap with fish cut into strips. Top with cabbage and tomato salads. Drizzle with additional garlic mayo if you like your sandwiches with lots of dressing.
Notes
If you don’t want to fry it, you can bake it. Preheat oven to 475°F. Coat the bottom of an oven-proof (such as cast iron) skillet with oil. Heat skillet over the stove until oil is hot and smokey. Add fish and spray the top with nonstick cooking spray. Place in oven until fish puffs up (it will not turn golden) about 8 minutes.