Pat the rockfish filets dry with paper towels. Place in an oven safe dish, sprinkle with pepper and place orange or pineapple juice in the dish. Marinating in the juice 20 minutes ahead of time can also be done to enhance the flavor!
Bake the fish at 350 F 30 minutes.
While the fish bakes, combine the rice wine vinegar, oil, soy sauce, red pepper flakes and tapioca flour in a saucepan. Bring to medium heat and whisk together until the tapioca flour is incorporated and the sauce begins to thicken.
Place the minced garlic and bell pepper in the pan. Sauté 5-7 minutes until the pepper is tender.
Add the pineapple to the saucepan and cook another 2-3 minutes.
Remove the fish from the oven and serve with the sauce over white rice, brown rice noodles, zucchini noodles or cauliflower rice.