Heat the oil in a large pot and add the onion and red pepper. Fry until soft.
Add the mussels, Spice For Fish, garlic, lemon juice and paprika, and season to taste with salt and black pepper.
Add the Barbecue Spice and stir together for 3 minutes.
Add the can of tomatoes, the crushed chillies and the contents of the sachet of KNORR Naturally Tasty Tuna Napolitana, and mix well.
Stir in the water, lower the heat and cook for another 30 minutes, stirring occasionally.
Add the mixed vegetables and simmer for another 15 minutes.
Serve hot with pasta or bread.