01 - Toss shredded cabbage, sliced red onion, chopped cilantro, lime juice, and a pinch of salt in a mixing bowl. Set aside to marinate while preparing other components.
02 - Combine avocado, sour cream, cilantro, lime juice, garlic, salt, and pepper in a blender or food processor. Blend until completely smooth and creamy. Adjust seasoning to taste.
03 - Whisk together flour, cornstarch, baking powder, salt, pepper, and paprika in a bowl. Gradually whisk in the cold sparkling water until smooth batter forms. The consistency should coat the back of a spoon.
04 - Pour oil into a deep skillet or pot to reach 2-3 inches depth. Heat over medium-high heat until temperature reaches 350°F.
05 - Pat fish strips dry with paper towels. Dip each strip into batter, allowing excess to drip off, then carefully place in hot oil. Fry in batches for 3-4 minutes until golden brown and crispy. Transfer to paper towels to drain.
06 - Place fried fish portions in warm tortillas. Top with fresh slaw and generous drizzle of avocado crema. Garnish with additional cilantro and serve with lime wedges on the side.