Prep all ingredients per instructions above.
Heat Vegetable Oil: In a large skillet or deep fryer, heat vegetable oil to 375°F (190°C).
Prepare the Fish: In a shallow dish, combine the flour, baking powder, water, chili powder, cumin, garlic powder, paprika, salt, and pepper. Stir until well mixed. Add more water if needed for a thick smooth batter. Dredge each fish filet in the batter, coating well.
Fry the Fish: Carefully place the coated fish filets in the hot oil. Fry for about 3-4 minutes on each side, or until golden brown and crispy to an internal temperature of 125℉ | 51℃ using a thermometer. Remove the fish from the oil and place them on a paper towel-lined plate to drain excess oil.
Prepare the Guacamole: In a bowl, mash the avocados with a fork until desired consistency. Add the diced red onion, jalapeño, cilantro, lime juice, and salt. Mix well to combine. Adjust seasoning to taste.
Warm the Tortillas: In a clean skillet, warm the corn tortillas over medium heat for about 30 seconds on each side.
Assemble the Tacos: Place a small handful of shredded cabbage on each tortilla. Top with a fried fish filet, fresh cilantro leaves, and a squeeze of lime juice. Repeat with the remaining tortillas and ingredients.
Serve the Meal: Arrange the Baja fish tacos on a plate. Serve with a side of chips and guacamole, and iced tea.