Prep: Cut fish into 2- to 3-inch pieces and pat dry with paper towels.
Mix salt, garlic powder, smoked paprika, cumin, and chili powder in a small bowl.
Season both sides of the fish evenly with the spice mix.
Toss the fish in cornstarch and shake off the extra so there’s a thin coating.
Heat oil in a skillet over medium heat.
Add fish in a single layer and cook for 3–4 minutes per side until golden and cooked through.
Warm tortillas in a dry pan or over a gas flame for a few seconds on each side.
Add pieces of fish to each tortilla and top with whatever you like.
Serve with lime wedges and eat while hot.