Combine the garlic powder, onion powder, and seafood seasoning in a small bowl. Set aside.

Pat the fish fillets dry with a paper towel. Sprinkle the fish on both sides with the seasoning mix and press gently to ensure it sticks.

Heat a medium skillet over low to medium heat. Add the butter and olive oil. Once the butter melts, add the fish. Cook for 3 to 5 minutes on each side. An instant read thermometer should read 145°F when inserted into the thickest part of the fish. The fish should be opaque and flake easily when done.

Remove the fish from the pan to a waiting plate. Let it rest for 5 minutes, then cut it into large pieces. Divide the fish evenly between the tortillas. Top with fish taco sauce and slaw.