1. Prepare the Tangy Slaw:
* In a large bowl, combine the shredded cabbage, shredded carrots, and thinly sliced red onion.
* In a separate small bowl, whisk together the mayonnaise, chopped cilantro, lime juice, apple cider vinegar, and honey/agave (if using). Season with salt and pepper to taste.
* Pour the dressing over the cabbage mixture and toss well to combine.
* Cover and refrigerate for at least 30 minutes (or up to a few hours) to allow the flavors to meld and the cabbage to soften slightly. This can be made ahead.

2. Prepare the Zesty Crema (if using):
* In a small bowl, whisk together the sour cream (or Greek yogurt), mayonnaise, lime juice, minced garlic (or garlic powder), and chopped cilantro.
* Season with a pinch of salt.
* If the crema is too thick, whisk in a teaspoon of water or milk at a time until it reaches a smooth, drizzling consistency.
* Cover and refrigerate until ready to serve. This can also be made ahead.

3. Prepare the Fish and Batter:
* Pat the fish strips dry with paper towels. This helps the batter adhere better and become crispier. Season lightly with a pinch of salt and pepper.
* In a wide, shallow dish or pie plate, whisk together the all-purpose flour, cornstarch, baking powder, smoked paprika, garlic powder, onion powder, cumin, cayenne pepper (if using), 1 teaspoon of salt, and 1/2 teaspoon of black pepper. This is your dry dredge.
* Take about 1/2 cup of this seasoned flour mixture and set it aside in another shallow dish – this will be used for lightly dusting the fish before dipping into the wet batter.
* To the remaining larger portion of the seasoned flour mixture, add the lightly beaten egg. Gradually whisk in the very cold lager beer or sparkling water until you have a smooth, thick batter, similar to pancake batter consistency. Don’t overmix; a few small lumps are okay. The coldness and carbonation are key for crispiness.

4. Fry the Fish:
* In a large, heavy-bottomed skillet, Dutch oven, or deep fryer, pour in vegetable or canola oil to a depth of about 1-2 inches.
* Heat the oil over medium-high heat until it reaches 350-375°F (175-190°C). Use a thermometer for accuracy. If you don’t have one, a small drop of batter should sizzle immediately and turn golden in about 30-60 seconds.
* While the oil is heating, lightly dredge each fish strip in the reserved 1/2 cup of seasoned flour mixture, shaking off any excess. This dry coating helps the wet batter stick.
* Dip each floured fish strip into the wet batter, ensuring it’s fully coated. Let any excess batter drip off for a moment.
* Carefully place the battered fish strips into the hot oil, working in batches of 4-5 pieces at a time to avoid overcrowding the pan (which would lower the oil temperature and result in greasy fish).
* Fry for about 2-4 minutes per side, or until the batter is deeply golden brown and incredibly crispy, and the fish is cooked through and flaky.
* Using a slotted spoon or spider, remove the crispy fish from the oil and transfer it to a wire rack set over a baking sheet to drain. Season immediately with a tiny pinch more salt while hot. The wire rack allows air to circulate, keeping the underside crispy. Avoid placing on paper towels directly, as this can make them steam and lose crispness.
* Repeat with the remaining fish, ensuring the oil returns to the correct temperature between batches.

5. Warm the Tortillas:
* While the fish is frying or resting, warm your tortillas. You can do this by:
* Stovetop (for char): Briefly heat them directly over a low gas flame or in a dry cast-iron skillet for about 15-30 seconds per side until pliable and lightly charred.
* Microwave: Stack them, wrap in a damp paper towel, and microwave for 30-60 seconds until warm and steamy.
* Oven: Wrap a stack of tortillas in foil and warm in a 300°F (150°C) oven for about 10 minutes.
* Keep warmed tortillas covered in a clean kitchen towel or tortilla warmer.

6. Assemble the Tacos:
* Take a warm tortilla. Place one or two pieces of crispy fish down the center.
* Top generously with the tangy slaw.
* Drizzle with the zesty crema (if using).
* Garnish with extra chopped cilantro, a squeeze of fresh lime juice, and sliced jalapeños or hot sauce if desired.
* Serve immediately and enjoy the delicious crunch!