No-waste spicy tomato fish stew

Method

1. Heat 1 tbsp of the oil in a large pan over a medium-high heat, then add the onion, celery, pepper, garlic, chilli and a large pinch of salt. Cook for about 12 minutes, stirring regularly, until golden. Stir in the tomato purée and cook for 2 minutes.
2. Add the fish heads, scraps and bones, then the wine. Bubble until almost evaporated, then add 1 litre water and the thyme. Bring to the boil, then reduce the heat and simmer gently for 45 minutes.
3. Take off the heat and pour into a blender (in batches if needed). Slowly at first, blend the broth and bones – take out the whole chilli first if you don’t want extra heat. Increase the speed until the mixture is ground to a near-smooth liquid.
4. Return the pan to a medium heat (no need to clean), add the tomatoes with the remaining 1 tbsp oil and cook for about 10 minutes to soften. Pour the whizzed broth through a fine sieve into the pan, pressing the solids with a wooden spoon to extract as much liquid as possible. Heat through for a few minutes, stirring. Season to taste with salt and pepper.
5. Cut the white fish fillets and sardine fillets into 4-5cm chunks and lower into the broth. Simmer for 1 minute, then stir in the spinach and cook for 1-2 minutes until the fish is opaque. Serve drizzled with oil, with rice or crusty bread on the side.