01 - Toss cabbage, red onion, cilantro, lime juice, and a pinch of salt in a bowl. Set aside to let flavors meld.
02 - Combine avocado, sour cream, cilantro, lime juice, garlic, salt, and pepper in a blender or food processor. Blend until smooth and creamy. Taste and adjust seasoning as needed.
03 - Mix flour, cornstarch, baking powder, salt, pepper, and paprika in a bowl. Gradually whisk in the sparkling water until you have a smooth batter.
04 - Heat oil in a deep skillet or pot over medium-high heat to 350°F.
05 - Pat fish strips dry with paper towels. Dip each strip into the batter, letting excess drip off, and carefully place in the hot oil. Fry in batches until golden and crisp, about 3-4 minutes per batch. Drain on paper towels.
06 - Place a portion of fried fish in each warm tortilla. Top with slaw and a generous drizzle of avocado crema. Garnish with extra cilantro and serve with lime wedges.