Cook the salted pork fat in a large pot over medium-high heat, stirring occasionally, until the fat is rendered and they are a nice golden brown, about 5 minutes.
Add the onions and cook until soft. Add the salt beef, cook for 3 minutes, and add the potatoes. Cover with 4 cups water and add salt and pepper to taste. Bring the soup to a boil and add the cod. Simmer until the cod turns from transparent to solid white, about 20 minutes.
Spoon the soup into bowls and garnish with the herbs.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.