First, make sure the salted cod has already been desalted and shredded. If it still tastes very salty, rinse it again and drain it well.
Next, heat the vegetable oil in a large pan over medium heat. Add the onion and cook until it starts to soften.
Then, add the garlic, tomatoes, and red bell pepper. Stir everything together and let it cook for a few minutes, until the tomatoes begin to break down.
Next, stir in the tomato paste, vinegar, and black pepper. Let it cook into the vegetables so the sauce gets richer and deeper in color.
Then, add the shredded bacalao to the pan and gently stir it into the sauce.
After that, lower the heat and let it simmer for about 8 to 10 minutes, stirring here and there so it doesn’t stick.
Finally, add the chopped parsley. Taste before adding salt, since the bacalao may already have enough. Add just a little if it needs it.