Make a crema: Mix together cour cream, mayonnaise, lime zest, and lime juice; taste and adjust seasoning and set aside.

Mix together cabbage, cilantro, red onion, and jalapeños; add enough of the sour cream mixture to moisten, reserving remaining crema.

Heat a cast iron griddle over medium-high heat. Sprinkle fish evenly with cumin, Creole seasoning mix, and peppers to taste; cut into ½-inch strips across the grain. Spray griddle with cooking oil and, working in batches if necessary, bronze fish on all sides, turning carefully; keep warm.

Working one at a time, place tortillas on hot griddle and warm, turning once, until softened and browned slightly.

To serve, divide cabbage mixture among tortillas. Top with fish, then garnish with avocado, tomato, and cilantro. Drizzle with reserved crema; serve with lime wedges.