Heat the oil in a large saucepan over a high heat, add the chopped garlic, onion and paprika and cook, stirring occasionally, for 5 minutes, until fragrant and the onions are golden and the liquid had evaporated. Add the chopped tomatoes, sweetcorn and fish stock and bring to a simmer. Add the cod fillets, return to a simmer and poach for 10 minutes. Remove the cod fillets with a slotted spoon and set aside.
Add the coriander, prawns and lemon juice to the pan and simmer for a further 2 minutes, until the prawns are cooked through. Flake the cooked cod and return to the pan.
Divide the soup between 4 bowls and serve with the extra lemon wedges and crusty bread.