In a small bowl, combine sour cream, mayonnaise, lime juice, and garlic powder. Stir in hot sauce to taste. Set aside.
Pat fish dry with a paper towel. Cut cod fillets into 8 evenly sized pieces. In a shallow dish, combine flour, cumin, salt, and pepper. Dredge fish lightly and shake off any excess.
In a large skillet over medium-high heat, add the oil and heat until shimmering. Add the cod and cook, turning once, about 8 minutes total, or until the cod is lightly golden, opaque, and flaky.
Meanwhile, warm the tortillas in a tortilla warmer or on a paper towel-lined plate in the microwave until soft. (see Tip)
Place slaw down the center of each tortilla. Top with cod and red onion. Drizzle with sauce.
Serve with lime wedges.
Notes
The nutrition information does not include the option toppings.