Line a baking sheet with foil. Place a cooling rack on top of the baking sheet and spray with olive oil or canola oil cooking spray.
Combine breadcrumbs, cornmeal and taco seasoning together in a shallow bowl.
In a separate shallow bowl, whisk the egg whites and lime juice until frothy.
Place flour in a shallow bowl.
Dip the fish strips gently into the flour to lightly coat on both sides. Dip into the egg whites and allow excess to drip off, then press the fish pieces on both sides into the seasoned cornmeal and breadcrumbs.
Place the breaded fish strips on the prepared rack and cook for 10 to 12 minutes, until the outside is golden crisp and the fish is opaque and flakes easily with a fork.
Coat a saute pan or griddle with cooking spray. Warm the tortillas over medium heat, for 30 seconds to 1 minute per side, until warmed through. Keep tortillas warm in a clean kitchen towel until ready to serve.
Place 2 strips of the fish into each tortilla, top with shredded romaine, salsa or tomato, and top with yogurt.