Prep the ingredients per the instructions above.
Preheat the oven to 400°F (204°C).
Place the fish on a baking sheet and season with lime juice, zest, oil, salt, and pepper. Set aside.
Make the topping: In a bowl mix the corn, black beans, avocado, radish, cilantro, and jalapeño (if using). Squirt some of the lime juice and season with salt and pepper.
Make the guacamole: Slice the avocados in half, remove the pit and skin, then place in a mixing bowl. Mash the avocado with a fork. Add the remaining ingredients (except the chips) and stir them together. Season with salt and pepper to taste.
Make the fish: Bake for about 10 to 15 min to an internal temperature of 125°F (51°C) using a thermometer. Then gently cut into pieces.
Warm the tortillas: Heat a cast iron or non-stick skillet over medium heat and warm each tortilla individually, flipping occasionally.
Assemble the tacos: Place the fish on the taco shells, and top with corn black bean mixture and queso fresco.
Margarita: Mix all the ingredients for the mocktail until combined. Serve over ice.
Serve: Enjoy the tacos with optional salsa verde or hot sauce on the side, chips and guacamole, and margarita mocktail.