To begin, peel the prawns and set aside the meat. Place the heads and shells in a pot with 1.5 litres of water, onion, carrot, garlic, and bay leaves. Simmer for 30 minutes, then strain and discard solids. Set stock aside and move to preparing the rice base.
In a wide pot, heat olive oil over medium heat. Add chopped onion and cook until soft and translucent. Stir in minced garlic and cook for one minute until fragrant. Proceed to add tomato base.
Add chopped tomatoes, tomato paste, and paprika to the pot. Cook until the tomato reduces and deepens in colour, around 8–10 minutes. Stir occasionally to avoid sticking. Move on to adding rice and deglazing.
Stir in the rice and coat well with the tomato mixture. Pour in the white wine and let it bubble for 1–2 minutes to remove alcohol. Season lightly with salt and pepper. Transition to adding stock.
Pour in 1 litre of the hot prawn stock and stir. Bring to a gentle simmer and cook uncovered for 10 minutes, stirring occasionally. Add more stock as needed to keep the mixture soupy. Move to seafood preparation.
Add the calamari rings and clams to the pot. Stir gently and cook for another 5–6 minutes. If any clams remain closed after cooking, discard them. Continue with mussels and prawns.
Stir in the prawns and mussels. Simmer for 3–4 minutes until the prawns are pink and the mussels open. Again, discard any unopened mussels. Adjust seasoning to taste. Prepare garnish next.
Remove from heat and cover the pot for 3 minutes to allow flavours to settle. Stir in fresh coriander. The final texture should be brothy, not dry. Move to plating.
Ladle the rice and seafood into shallow bowls. Garnish with extra coriander and lemon wedges. Presentation tip: Serve with crusty bread to soak up the broth and a chilled glass of white wine to complete the coastal experience.