Step 1Place tortillas in covered heat-proof container or sealed aluminum foil packet; put fish in similar container. Warm tortillas and fish in 200-degree oven 15 minutes before serving.
Step 2Toss together cabbage, green onions and lime juice in medium serving bowl. Place diced tomatoes in serving bowl. Put sauce in serving bowl. When tortillas and fish are warm, set on separate serving plates.
Step 3Let each diner assemble his or her own tortilla. To assemble: spread a little sauce down middle of tortilla, add some fish, sprinkle with diced tomatoes, then garnish with cabbage mixture.