Umbrian cooking has always used natural products that give a vast range of possibilities in varieties of taste and preparation.
Between the richness of the Umbrian products we must not forget the fish of the rivers and lakes, fish of which are particularly abundant in the lake of Trasimeno where they are fished with a net; one of the most widely used is that of the altana, a vertical net left usually to function over a few hours waiting for the fish to become entangled in their attempts to go through.
The measurment of the nets vary from twentyfive millimetres, used for the type of fish such as the royal bass, whereas that used for the tench fish is bigger by thrity to fifty millimetres.
Other than fish such as the royal bass and the tench, of which can be made exquisite risotto, there is also fished the pike, catfish, bleak, ells and many others. In the lacustrine environment there occurs over a period of time, transformations attributed in part to normal evolution of the ecosystem, and in part to human intervention. In the course of this century there have been activated regularly practices of restocking lake Trasimeno; and so the catfish (which can make a flavoursome spaghetti dish) and the bleak, that were at risk of extinction, are today on the way to expansion.
The carbonetti are famous - small fish so called because they are black like coal - which are fished above all in the lake of Piediluco and are very tasty if cooked on the sarmenti (the remains from the trimmimgs of the vines). Only after being cooked are they cleaned of skin, bones and entrails; they are then seasoned with olive oil, salt and pepper and are eaten hot.
In the rivers there are fished, above all, sweet water prawns and trout that offer excellent possibilities of combining with black truffles, enough to think of the «tagliolini con tartufo nero di Norcia e filetto di trota», a true delicacy.
Of the importance, particularly in the past, of the fish of lake Trasimeno this is testified to by the Museum of Fishing at San Feliciano.