Place the fish in a large glass dish and toss with 2 tbsp of the lime juice and 1 tsp salt. Cover and place in the fridge for 30 minutes to marinate.
Serve with the rice, garnished with the coriander.
Meanwhile, heat the oil in a large saucepan over a medium heat. Add the onion and cook for 4 minutes or until softened. Add the red pepper, garlic and chillies, and cook, stirring occasionally, for a further 5 minutes or until the pepper is softened.
Stir in the stock, tomatoes, coconut milk and coconut oil. Bring to the boil, then reduce the heat to medium and cook for 12–15 minutes until the sauce is slightly reduced.
Add the prawns, fish and marinating juices, and cook for a further 3–4 minutes until the seafood is just cooked through. Stir in the remaining lime juice and season to taste.