Method

• 1.
  For the stock, heat oil in a large non-stick frypan over medium-high heat. Fry mullet bones for 2 minutes each side. Transfer to a large saucepan. Reduce heat to medium. Add carrot, celery, fennel and garlic to the frypan and cook, stirring occasionally, for 3-4 minutes until starting to soften. Deglaze pan with wine and cook until almost completely evaporated. Transfer vegetable mixture to saucepan with the fish bones. Add saffron and 1L (4 cups) water. Bring to a simmer and cook, without stirring, for 30 minutes. Don’t let it reduce more than half; you will need 2 cups (500ml) stock. Strain through a fine sieve lined with muslin.
• 2.
  Meanwhile, for the onion puree, heat anchovy oil in a small saucepan over medium-low heat. Add onion and cook, stirring occasionally, for 4-5 minutes, until translucent. Reduce heat to low, add anchovies and cook, covered and stirring occasionally, for 20 minutes or until onion is very soft and moist (you may need to add some water if it starts sticking or gets too dry). Remove pan from heat. Stand, covered, for 5 minutes, then, while still hot, blend with a stick blender to a very smooth puree.
• 3.
  Bring a large saucepan of salted water to the boil. Add pasta and cook following packet instructions until almost al dente.
• 4.
  Meanwhile, heat 2 tbs olive oil in 2 large, deep frypans over medium-low heat (see note). Divide garlic and chilli between the pans and saute gently for 1 minute until softened but not coloured. Add the saffron stock to both pans, then 2 tbs onion puree. Bring to a simmer.
• 5.
  Meanwhile, heat remaining 1 tbs oil in a large non-stick frypan over medium-high heat. Cook mullet, skin-side down, for 3-4 minutes until skin is crispy and flesh tu ns opaque (no need to cook the other side of this small, delicate fish). Set aside. Break into large bite-sized pieces before serving.
• 6.
  Once pasta is ready, use tongs to transfer straight from the saucepan to the frypans with the simmering sauce. Working quickly, toss over a low heat for 1-2 minutes to combine well, finish cooking the pasta until al dente and generate a thickened, reduced sauce. Remove pans from heat and toss through lemon zest and juice and fennel fronds, and season to taste with sea salt.
• 7.
  Keep tossing until sauce coats the pasta really well. You may need to add a little pasta cooking water if it becomes too dry.
• 8.
  Swipe a small spoonful of onion puree on a plate and top with pasta and red mullet pieces. Drizzle with leftover saffron pan juices and sprinkle with extra fennel fronds to serve.