1 tbsp. olive oil
2 onions, halved and thinly sliced
2 celery stalks, finely chopped
large bunch flat-leaf parsley, leaves and stalks separated
2-3 tsp paprika
200 g roasted red peppers, drained weight, thickly sliced
400 g can chopped tomatoes with garlic
400 g white fish fillet, cut into very large chunks
few fresh mussels (optional)
1. Leave this stew to infuse for longer. Whizz the parsley stalks, half the leaves, oil and seasoning in a food processor. Add this to the onions, celery, paprika, peppers and tomatoes in the slow cooker pot. Cook on Low for 8-10 hours. Nestle the mussels in the sauce and scatter the fish on top. Re-cover and cook on High for 30 mins-1 hour. Discard any unopened mussels, stir the fish into the sauce then serve.
2. Heat the oil in a pan, then add the onions, celery and a little salt. Cover, then gently fry until soft, about 10 mins. Put the parsley stalks, half the leaves, oil and seasoning into a food processor and whizz to a paste. Add this and the paprika to the softened onions, frying for a few mins. Tip in the peppers and tomatoes with a splash of water, then simmer for 10 mins until the sauce has reduced.
3. Lay the fish and mussels on top of the sauce, put a lid on, then simmer for 5 mins until the fish is just flaking and the mussels have opened – discard any that stay shut. Gently stir the seafood into the sauce, season, then serve in bowls.