Mediterranean fish stew with straw potatoes

Method

1. Heat the oil in a large sauté pan and add the onions, fennel and celery. Toss to combine with the oil, season with salt and pepper, then cook over a low-medium heat for 10-15 minutes, stirring often, until softened but not coloured. When the veg is tender, stir in the anchovy, garlic, chilli flakes and saffron strands, then cook for a few more minutes until fragrant.
2. Add the tomato purée with the sugar, stir and cook for another 3-4 minutes. Turn the heat up and add the wine. Bubble until almost evaporated, then add the bay leaf and fish stock. Bring to a simmer and cook for 15 minutes until reduced to half its volume.
3. While the stock mixture reduces, make the straw potatoes. Cut them into strips using a julienne peeler (see Know-how) or a mandoline, or the julienne attachment on a food processor. Soak in cold, heavily salted water for 15 minutes, then drain and pat dry.
4. Turn the oven to its lowest setting. Heat 4cm oil in a large frying or sauté pan and, when shimmering hot, drop in a couple of potato strands to see if it’s hot enough – they should sizzle on impact. Cook the straws in 2-3 batches, swirling them round a little with a fork for 4-5 minutes, until lightly golden and crisp. Remove with tongs, drain on kitchen paper and season with salt. Keep warm in the oven.
5. Chop the fish fillets into large chunks. Rinse and scrub the mussels and clams, removing any threads (beards) from the mussels. Make sure the stew base is gently simmering, then stir in the crabmeat. Drop the prawns and shellfish into the pan, followed by the fish chunks and the reserved fennel fronds around a minute later. Cover with a lid and cook for 3-4 minutes, moving things around every so often to distribute the heat, until the fish has turned opaque, the mussels and clams have opened (remove and discard any that don’t open) and the prawns are completely pink. Taste and season with salt, pepper and lemon, adding a slug of pastis if you have it (see tip). Divide the stew among shallow, wide bowls, top with straw potatoes and scatter over the parsley. Serve immediately, with lemon wedges.