In total about 5 lb of fish (about 2.5 kilograms):
monkfish (coda di rospo or rana pescatrice),
skate wings skinned (razza), shrimps (gamberi),
mantis shrimp (canocchie or pannocchie),
4-5 tablespoons extra-virgin olive oil
1 onion, chopped
1-1/2 cups tomato puree
1 tablespoon tomato concentrate
2 tablespoons white wine vinegar
In a large skillet on medium heat, place the olive oil.
Add the onion. Sauté until the onion is soft and translucent.
Add tomato puree and tomato concentrate. Add vinegar. Stir to combine and cook for about 5 minutes. Add salt and pepper.
Add the fish at intervals, starting from those who take longer to cook. Squid first, then larger fishes followed by small fishes, skate, mullet, shrimps and mantis shrimps. Finally add the mussels and clams.
Add a little bit of water if the sauce is too think.
The stew is ready when the fish is thoroughly cooked and the mussels and clams are open.
We served it hot accompanied by a bottle of Verdicchio wine.