Seafood Paella

Heat the fish stock in a saucepan and keep it hot. Clean the squid and cut the bodies into rings. Halve the tomatoes and grate the cut sides on a box grater, discarding the skins. Finely chop the onion and the garlic, and trim the green beans if using. Scrub and debeard the mussels, throwing away any open ones that do not close when tapped. Cut the lemon into wedges.

Steep the saffron threads in a ladleful of the hot stock.

Fry the squid rings in the olive oil in a wide paella pan (about 38 to 40 cm across) for 2 minutes and lift them out. Soften the onion in the same oil, then add the garlic and the sweet paprika and stir for 30 seconds.

Add the grated tomato and cook it down to a dark, jammy sofrito, about 8 minutes. This is where the flavour comes from, so do not hurry it.

Stir in the rice and the green beans, if using, until every grain is coated, then pour in all but a ladleful of the stock and the saffron liquid. Season with salt and spread the rice flat.

From here, do not stir. Boil hard for 10 minutes, then lower to a simmer for 8 more minutes.

Press the prawns and the mussels, hinge down, into the surface of the rice, scatter over the squid and cook for a final 5 minutes, turning the prawns once, until they are pink and the mussels have opened. Discard any mussels that stay shut. If the rice is still hard when the liquid has gone, sprinkle over the reserved stock, heated, without stirring.

Turn the heat up for 60 to 90 seconds and listen for a faint crackle — that is the socarrat forming underneath. Pull it off the heat the moment you smell toast.

Cover with a cloth and rest for 5 minutes. Serve from the pan with lemon wedges.