Preparation time: 10 minutes
Cooking time: 35 minutes+ 20 minutes for the long version
 

A good broth made with a fish head is delicious and flavorful; otherwise use fish pieces.

Long version

1. Prepare the broth: place about 2 liters (8 cups) of water in a large pot; bring to a boil and add the fish head and grouper pieces.
2. Cook, covered, for 20 minutes. Strain the broth. There should be about 1 1/2 liters.
3. Flake the fish flesh and set aside.
4. Sauté the chopped onion, parsley, celery, finely diced garlic and tomato concentrate in oil..
5. Add the broth. Cook for 20 minutes.
6. Add the pasta to the pot, which will take 15 minutes, at most, to cook. Before the end of the cooking time, add the flaked fish.

Short version

1. Sauté the chopped onion, parsley, celery, finely diced garlic and tomato concentrate in oil.
2. Add the water. Cook for 20 minutes.
3. Add the fish to cook without cutting it up. Once it is cooked, remove it, skin and debone it, and crush the flesh coarsely with a fork. Return the fish to the pot. Add the pasta, which will take 15 minutes longer, at most, to cook.