Season both sides of the fish with a few generous pinches of salt and pepper.
Heat oil in a large saute pan over medium-high heat. Add the fish and cook for 2-4 minutes per side, until the fish is cooked through and opaque and flakes easily. (Cooking time will depend on the size/thickness of your fish.) Remove from heat and transfer fish to a separate plate. Use two forks to flake the fish into bite-sized pieces.
Assemble your tacos by layering the following on flour tortillas: cabbage, fish, tomatoes, olives and cucumber. Then top with feta and tzatziki to taste. Serve warm, with lemon wedges for a squeeze of juice.
*If you are making these gluten-free, use GF corn tortillas instead of flour. Since corn tortillas can tend to break easier, I recommend using two tortillas per taco and warming them before filling.
**All portions are just suggestions. You can use as much or as little of each topping as you’d like! :)