While the ingredient list is long, most of the work is simply measuring out seasonings and prepared ingredients. The dish comes together in less than 30 minutes. Substitute any firm white fish, such as red snapper or flounder, for tilapia.
Preheat oven to 425º.
Place tortilla strips on a baking sheet lined with foil; lightly coat tortilla strips with cooking spray. Sprinkle strips with 1/2 teaspoon chili powder and 1/4 teaspoon salt. Bake at 425º for 10 minutes or until crisp, and set aside.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, cornmeal, onion flakes, and the remaining 1/2 teaspoon chili powder in a shallow dish. Sprinkle fish with 1/4 teaspoon salt; dredge in cornmeal mixture.
Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat. Add fish; cook 3 minutes on each side or until browned and fish flakes easily when tested with a fork or until desired degree of doneness.
Combine romaine and next 4 ingredients (through cilantro) in a large bowl. Combine juice, mustard, and remaining 1/4 teaspoon salt in a small bowl, stirring with a whisk. Gradually add remaining 4 teaspoons oil, stirring constantly with a whisk. Drizzle juice mixture over lettuce mixture; toss gently to coat. Place 1 1/2 cups salad mixture on each of 4 plates; sprinkle each serving with 1 tablespoon cheese. Place 1 fish fillet on each salad; top with 5 tortilla strips.