Start by preparing the marinade. In a large bowl, combine the white vinegar, brown sugar, and all the spices. Mix well.
Add the fish to the marinade, making sure each piece is well coated. Cover the bowl and let it marinate in the refrigerator for at least 30 minutes.
While the fish is marinating, prepare the vegetables. Slice the onion, bell peppers, and carrots. Mince the garlic.
In a separate bowl, mix the flour and cornmeal. Dredge the fish in the mixture, shaking off any excess.
Heat the vegetable oil in a large pan over medium-high heat. Once the oil is hot, add the fish and cook for about 2-3 minutes per side, or until golden brown.
Remove the fish from the pan and set it aside on a plate lined with paper towels.
In the same pan, sauté the vegetables until they are slightly soft. Add the garlic and cook for an additional minute.
Add the marinade to the pan and bring it to a simmer. Let it cook for about 2-3 minutes, or until the sauce has thickened.
Return the fish to the pan and spoon the sauce over the top.