Soak the saltfish in water overnight or for at least 8 hours, changing the water a few times to remove excess salt. After soaking, drain and rinse the saltfish. Boil in fresh water for about 10 minutes, then drain and flake the fish into pieces.
Heat the vegetable oil in a large skillet or pot over medium heat. Add the chopped onion, garlic, and bell pepper. Sauté until the onion is soft and translucent.
Stir in the diced tomatoes, Scotch bonnet pepper (if using), thyme, paprika, black pepper, and allspice. Cook for about 5 minutes until the tomatoes are softened.
Add the flaked saltfish to the skillet. Stir in the tomato paste and water or vegetable broth. Add the diced potato. Mix well.
Bring the mixture to a boil, then reduce the heat to low. Cover and simmer for about 20-25 minutes, or until the potatoes are tender and the flavors are well combined. Stir occasionally and add more water or broth if needed.
If using, stir in the sliced green olives. Garnish with fresh parsley or thyme before serving.
Enjoy your meal!