Ration fish, also known as lliseria or northern gallo, is a flat fish highly valued for its delicate flavor and low fat content, which is less than 2 grams per 100 grams of edible portion. This specimen belongs to the flatfish family and is commonly found in the waters of the northeastern Atlantic, as well as in the North Sea and the Mediterranean. It is usually offered in clean, whole pieces ranging from 300 to 400 grams, making it an ideal choice for hypocaloric diets, as it can be cooked grilled or baked, minimizing caloric content. However, when fried or breaded, the fat content may increase. Nutritionally, the ration fish stands out due to its high biological value protein and is a source of B-group vitamins, such as B6 and B9, as well as minerals like phosphorus, potassium, magnesium, and iodine. It is a healthy and versatile option for any meal.