1. Heat the oil in a large pot. Add garlic, chili and parsley stalks and stir well. Add the white wine and cook over medium heat for 2-4 minutes or until the alcohol evaporates.
2. Add the reserved prawn stock, Mutti Polpa and 400ml of water. Stir well and season with salt. Cook over medium-low heat for 30 minutes with the lid on. The stew should be reduced by a third - if it hasn’t, cook for a further 10 minutes with the lid off.
3. The sauce can be cooled and refrigerated until you are ready to cook the fish. It will keep in the fridge for 24 hours.
4. Before you are ready to serve bring the sauce to simmer and remove the capsicum quarter. Add the mussels and vongole, cover with a lid and steam until open. Add the ling and prawns, cook for 30 seconds then turn off the heat and cover with a lid, to allow the residual heat to continue cooking the fish for a few minutes, while you get the bowls and grill the bread. Serve in individual bowls, piping hot with grilled sourdough and chopped parsley.