Start by making the stock. Peel and roughly chop the onion, then peel the garlic, keeping them whole.
Heat 3 tablespoons of olive oil in a large pan over a medium heat and sauté the onion, garlic, paprika, bay leaves and prawn shells and heads for 10 minutes, stirring occasionally.
Add the wine and fish stock and bring to the boil. Lower the heat and simmer for 30 minutes, or until it starts to reduce.
Strain through a colander into a large jug and set aside until needed (when you come to make the paella, just reheat the stock until hot, but not boiling).
For the sofrito, peel and dice the onions and garlic, then add to a large frying pan over a medium-low heat with 3 tablespoons of olive oil and the paprika. Fry for 7 to 8 minutes, or until softened and golden.
Pour in the wine and simmer for 1 to 2 minutes, then coarsely grate in the tomatoes, discarding the skins. Stir and cook for 5 minutes.
Lower the heat and simmer for another 30 minutes, or until the mixture has thickened into a lovely sauce. Transfer to a bowl until ready to use.
To make the paella, deseed and roughly chop the peppers. Cut the monkfish into large chunks, then slice the squid. Wash the mussels and clams thoroughly, discarding any that remain open when tapped.
Heat half of the olive oil in a large paella pan over a medium heat and cook the peppers for 5 minutes, until softened. Transfer to a separate bowl with a slotted spoon. Set aside.
Add the monkfish to the pan, season generously and cook for 10 minutes, or until tender. Set aside in a bowl.
Throw the squid into the pan and cook for 1 to 2 minutes, then tip it into the bowl with the monkfish. Set aside until ready to use.
Add the remaining oil to the pan, scatter in the rice in an even layer and sauté over a medium heat, stirring, for 5 minutes, or until the rice is golden.
Stir the sofrito into the rice and cook for 2 minutes, then add the hot prawn stock and bring the mixture to the boil for another 2 minutes.
Sprinkle the saffron and paprika over the rice, reduce the heat to low and simmer, without stirring, for 10 to 12 minutes, or until all the liquid has almost been absorbed.
Arrange the peppers, monkfish, squid, prawns, mussels and clams evenly around the top of the paella. Cook for about 8 minutes, turning the prawns halfway through, or until the mussels and clams have opened (discard any that don’t) and the prawns are cooked.
Drizzle with a little extra virgin olive oil, cover the pan with tin foil and a few clean tea towels and allow to rest for 5 minutes before serving.