Like many fish stews, tegamaccio has numerous variations, but lots of tomatoes are key, with some kind of toast on the side. In Puglia they make it with clams, mussels, red mullet, squid and prawns white wine, capers and herbs.
On the banks of Lake Trasimeno in Umbria, they boil the fish heads with tomatoes to make the stock, strain it, and then add onions, garlic, peperoncino and pieces of lake fish (tench, carp, perch, etc).
Image by Umbria Turismo