Preheat oven to 375°F. First, prepare the fish. In a medium-sized bowl, combine bread crumbs, garlic powder, ½ of the taco seasoning mix, and salt to taste. Dip individual fillets in milk, and transfer to bread crumb mixture until completely coated on all sides. Place on a cookie sheet, lined with aluminum foil. Repeat until all fillets have been breaded. Spray all sides of breaded fillets with a light coating of olive oil. Place in pre-heated oven for 10 to 15 minutes or until golden brown and slightly crispy.
While fish is baking, mix together in a separate bowl, all ingredients for the Baja sauce. Place in refrigerator until fish is ready. When fish is done baking, heat the tortillas in the stove until warm, or microwave for 35 seconds. Assemble tacos by adding 2-3 fillets, shredded cabbage, and Baja sauce to each tortilla. Top with chopped tomato. Serve.