Toss sliced cabbage with cider vinegar and set aside.
Mix chili powder, cumin, and salt in a small bowl.
Pat fish fillets dry and coat both sides with spice mixture.
Heat oil in a large skillet over medium-high heat.
Cook fish 3 minutes per side until opaque and lightly browned.
Break cooked fish into bite-sized pieces.
Warm tortillas on a dry skillet or in microwave.
Layer two tortillas together, add fish, cabbage slaw, and cilantro.
Serve with lime wedges.