Preheat the oven to 400 degrees F. Line a baking sheet with foil and lightly coat with cooking spray.
In a glass container, whisk together the olive oil, lime juice, cumin, salt and pepper.
Add the fish, turning to coat with the marinade. Let rest for 15 minutes.
Transfer the fish to the lined baking sheet. Discard the marinade.
Bake until the fish is just cooked through, 8 to 10 minutes, depending on the thickness of the filets.
Let the fish rest until it is cool enough to handle, then flake with your fingers or a fork.
Heat a nonstick skillet over medium heat. Heat each tortilla until warm, about 10 seconds per side.
Divide the fish, salsa and cheese evenly between the tortillas. Serve.