Preheat oven to 400 degrees F (204 C), and line a large baking sheet with parchment paper.
Cut the fish into large cubes (or strips if you prefer) and add to a medium mixing bowl. Top with oil, salt, pepper, cumin, chili powder, smoked paprika, cayenne pepper (optional), and cornmeal (optional). Toss to coat. The fish should be so well coated that you almost can’t see it anymore. Don’t be shy with the spices!
Transfer to parchment-lined baking sheet, arrange in a single layer, and bake for 10-12 minutes or until fish is cooked through.
In the meantime, prepare any sides, such as guacamole, fresh herbs, and lime wedges.
To serve, warm tortillas and top each with 1 Tbsp guacamole and 2 pieces of fish, and serve with lime wedges. Serve with quick pickled veggies, chipotle aioli, and/or fresh cilantro for more flavor and texture (all optional).
Store leftover cooked fish separately up to 2-3 days. Cooked recipe is not freezer friendly.
*Nutrition information is a rough estimate calculated with homemade tortillas and 1 Tbsp guacamole per taco, and without optional ingredients.