In the pot your fried your fish, add onions and saute on medium heat for about 5 minutes. Add your minced garlic and saute for a minute then follow with your chopped tomatoes. And saute until reduced, mixing constantly to make sure there is no burning.
Add your tomato paste, your garlic powder, onion powder, paprika, cayenne, and stir making sure there is no burning. Season with salt to taste.
Add water or stock into the pot and season with more salt to taste. Add about 2 cups of water to the tomato broth forms. Taste and adjust, you want it to be salty enough because this is the broth the vegetables are going to be cooked in.
Prep your vegetables by peeling and cutting to your size preference. Typically Thieboudienne has largely chopped veggies e.g. quartered cabbage or sweet potato cut in half.
Add your vegetables in batches, starting with the vegetables that take the longest to cook so the potato and carrots. Once those are cooked through, set aside and cover to keep warm.
Follow with the other vegetables like cabbage, eggplant, okra, and bell pepper. Boil until they are all done or to your liking then set aside and cover, leaving the remaining tomato broth in the pot.