Place the fish filets on a small baking sheet or baking dish with sides. In a medium bowl, combine the lime juice, orange juice, chipotle sauce, garlic powder, cumin, chili powder, salt, and oil. Whisk to combine and pour half of the amount over the fish. Set aside the remainder. Cover fish with plastic wrap and marinate in the refrigerator for 30 minutes.
Preheat oven to 425°F. Once marinated, remove the plastic wrap and roast along with the marinade in preheated oven until the fish reaches 120°F and flakes easily. Remove from oven and allow to rest 5 minutes. After resting, use forks to lightly flake into bite-size pieces.
For the slaw
To the remaining marinade, add the sour cream and whisk to combine. Pour over shredded cabbage, green onion, and cilantro. Add in pickled jalapeño, if desired. Stir to combine. Cabbage can be made 24 hours in advance and stored in the refrigerator.