Combine ½ cup oil, 1 teaspoon of salt, and ½ teaspoon of black pepper in a small bowl. This will be your marinade for the fish.
Place fish in a large plastic bag or a covered dish and add marinade. Marinate the fish for up to 1 hour.
In the meantime, prepare the slaw by combining the cabbage, mango, avocado, onion, and cilantro. You may also leave the toppings separate and let everyone choose their own toppings.
Prepare the slaw dressing by combining 2 tablespoons of oil, 1 tablespoon of lime juice, and ¼ teaspoon of salt. Whisk the dressing and drizzle it over the slaw mixture or set aside to drizzle over fish if you're opting to do choose your own toppings.
Prepare the chipotle sour cream by adding 1 teaspoon of chipotle chili powder and ¼ teaspoon of salt to 1 cup of sour cream and mixing well.
Just before serving, heat a large pan over medium high heat and add a tablespoon of oil. Grill the fish for approximately 2 to 3 minutes per side. Fish is ready as soon as if flakes apart when you test it with a fork.
Serve with flour or corn tortilla (when using corn tortillas, we like to crisp them up in a pan for a few minutes on each side. Use some cooking spray to prevent sticking and add flavor).
Layer each tortilla with slaw/toppings of choice, followed by fish, and drizzled chipotle cream.
Nutrition estimate does not include tortillas; see nutritional information for tortilla depending on whether you use corn or flour.