01 - Combine green and red cabbage, carrot, and cilantro in a large bowl. Whisk mayonnaise, lime juice, salt, and pepper in a small bowl. Pour dressing over vegetables and toss thoroughly. Refrigerate until assembly.
02 - Mix sour cream, mayonnaise, lime juice, garlic powder, and salt in a small bowl until smooth. Set aside at room temperature.
03 - Pat fish fillets dry with paper towels. Whisk flour, baking powder, salt, pepper, and paprika in a medium bowl. Beat egg with sparkling water in another bowl, then pour into dry ingredients. Whisk until just combined—batter should remain slightly lumpy.
04 - Heat 1 inch oil in a deep skillet over medium-high heat to 350°F. Dip fish strips into batter, allowing excess to drip off, then carefully lower into hot oil. Fry in batches for 3–4 minutes, turning once, until golden brown and crispy. Transfer to paper towels to drain.
05 - Place crispy fish strips in warm tortillas. Top generously with cabbage slaw and drizzle with crema. Garnish with fresh cilantro leaves and serve immediately with lime wedges on the side.