Prepare the Mussels: Wash the mussels under running water, removing any barnacles with a stiff brush and pulling off the byssus thread. Once clean, put them in a pot, cover with a lid, and cook over high heat for about 5 minutes until they open. Set aside some whole mussels for garnish and remove the rest from their shells.
2.2 pounds mussels
Clean the Octopus: Clean the octopus by removing the beak and innards, then cut the tentacles into chunky pieces.
1.4 pounds octopus
Prepare Cuttlefish and Squids: For the cuttlefish, gently pull away the head and tentacles from the body. Wash thoroughly and remove the cuttlebone and ink sac. Chop the tentacles and head. Clean the squids by pulling out the head and inner cartilage, then peeling off the outer layer. Open the body flat, cut into strips, and then into smaller pieces.
Prepare Monkfish and Scorpionfish: Remove the skin from the monkfish, fillet it while keeping the bones and scraps aside. Do the same with the scorpionfish—scale, remove the head and fins, and fillet, keeping any scraps for the broth.
Clean the Shrimps: Use scissors to cut and remove the shrimp tails, legs, and carapace, leaving the head intact. Keep all scraps for the broth.
Start the Fish Broth: Chop additional onion and celery for the broth, mince another garlic clove. In a large pot, sauté these with the fish scraps (monkfish, scorpionfish, shrimp) for a few minutes. Add whole black peppercorns and a bunch of parsley. Deglaze the pot with white wine, then add water. Bring to a boil, reduce to a simmer for 40-50 minutes. Skim any foam from the surface. Strain the broth and set aside.
Sauté for Cacciucco Base: In a separate large pot, finely chop another onion, a garlic clove, and a chili pepper. Sauté these in olive oil until softened.
Cook Octopus, Squids, and Cuttlefish: Add the chopped octopus to the pot and cook for about 10 minutes. Then, add the squids and cuttlefish, continuing to cook for another 5 minutes. Pour in some white wine and let it evaporate.
Combine with Tomatoes and Broth: Season with salt and pepper, then stir in the crushed canned tomatoes and about 1 cup of the prepared fish broth. Cover and simmer on low heat for about 1 hour and 10 minutes.
Add Monkfish, Scorpionfish, and Shrimps: Carefully mix in the monkfish and scorpionfish pieces, followed by the shrimps. After 10 minutes, add another 2 cups of fish broth and continue cooking.
Final Addition - Mussels: Finally, add the previously cooked mussels (both shelled and whole) to the pot, and cook for an additional 10 minutes.
Prepare Garlic Bread: While the stew is finishing, slice the bread and toast it under the broiler for about 5 minutes, until crispy. Rub each slice with a clove of garlic for extra flavor.
Finish and Serve: Once the cacciucco is ready, stir in the chopped parsley for freshness. Serve the stew hot, accompanied by the toasted garlic bread for dipping.