Preheat the oven to 400 degrees Fahrenheit. Thaw the fish, if necessary.

In a small bowl, mix together the dry rub: chili powder, cumin, smoked paprika, garlic powder, and onion powder. Pat the fish dry, then sprinkle it with 1 teaspoon kosher salt and pat it in. Add the seasoning and pat it to cover the fish. Place the fish on a parchment lined baking sheet. Bake for 10 minutes, until tender. Then broil for 2 minutes until the top is lightly browned.

Meanwhile, thinly slice the cabbage. Shred or grate the carrot. Thinly slice the green onion. Place the cabbage, carrots, and green onion in a bowl. Stir in the lime juice, salt, and celery salt. Serve immediately with a slotted spoon. The slaw picks up moisture as it sits; if you plan to let it sit, make sure to serve with the slotted spoon to strain out the moisture.

Make the Fish Taco Sauce.

If desired, char the tortillas by placing them on an open gas flame on medium for a few seconds per side, flipping with tongs, until they are slightly blackened and warm. Or warm them according to How to Warm Tortillas.

Assemble the tacos by topping the tortillas with fish, slaw, and sauce. Top with chopped cilantro and a spritz of lime.