In a bowl, whisk together the flour, garlic powder, onion powder, paprika, salt and chili pepper. Pour in the beer and whisk until a smooth batter forms.
In a large nonstick skillet, heat the oil over medium-high heat. Working in batches, dip the fish in the batter and coat in completely, then drop it in the skillet to fry. Let each piece of fish fry for 6-8 minutes, turning once, or until golden and crispy and it flakes easily. Gently remove the pieces with a spatula and place them on a paper towel-lined plate to absorb any liquid. Repeat with all the fish, adding more oil if needed.
Heat a large skillet over medium heat and add about 1 teaspoon of olive oil. Add tortilla and cook for 4 minutes, turning once, or until golden and crisp on both sides. Remove the tortilla and set it on a paper towel to drain any excess oil and cool and crisp up slightly. Repeat with the remaining olive oil and tortillas.
Top the tortillas with butter lettuce and avocado. Add on the fish and top with cabbage, jicama, radishes, cilantro, and queso fresco. Enjoy!