Prepare the fish ready for cooking and set aside. Save the scraps. Rub the garlic and pods in a mortar with a little water to make a paste. Place in a caldero, a large cast iron casserole, mold. Fill with water. Peel, seed and chop the tomatoes. Remove the skin from the onion and cut it into quarters. Clean the carrot and cut it into slices. Put the vegetables in the saucepan with the fish scraps, season with salt and pepper. Bring to a boil and simmer on low heat for about 60 min.
Strain the fish stock through a sieve. Rinse the saucepan and return half of the fish stock to the saucepan, add the saffron. Bring the fish stock to the boil and cook the long grain rice in it for about 20 minutes so that it remains very juicy.
First bring the long grain rice to the table.
Poach the fish in the remaining fish stock. Arrange on a platter and offer with garlic sauce as a second course.