Put 1.2 litres fish stock in a saucepan and bring to a simmer.
Poach the 200g fish pieces or trimmings for 1-2 minutes or until just cooked.
Strain the stock, setting both the liquid and the cooked fish to one side.
In a separate large saucepan, heat 2 tbsp olive oil.
Add 1 finely chopped onion, 3 grated garlic cloves, 2 tsp paprika, 2 tsp ground cumin and 2 tsp tomato purée and cook over a low-medium heat for 2-3 minutes, stirring every so often, without colouring.
Pour in the reserved fish stock and simmer for 15 minutes.
Add the drained chickpeas and 2 roughly chopped tomatoes, season and simmer for another 15 minutes.
Taste the soup, re-season if necessary and stir in the cooked fish.
Add 2 tbsp chopped coriander then spoon into bowls and serve.