Preheat your oven at 400°.
In a medium bowl, combine tomatoes, red onions, 1 tablespoon lime juice, lime zest, vinegar, 1 tablespoon olive oil, and half of the cilantro. Cover and set aside.
In a separate bowl, combine the lettuce leaves and the remainder of the cilantro and place in refrigerator.
Cut fish lengthwise into 1 inch strips then cut the fish strips in half. Coat fish with the remainder of olive oil, lime juice, salt, pepper and chili powder. Arrange fish on a baking sheet and bake until the fish is opaque, approx. 5-8 minutes.
Take fish out of the oven and carefully place fish in tortilla shell, add salsa, lettuce, cheese and serve.
*If using soft tortillas, place in microwave-safe dish, wrap tortilla with paper towel and microwave for 1 minute.