Preheat oven to 200ºC/180ºC fan/gas 6. Sprinkle the saffron threads into a small heatproof glass or bowl and pour over 2 tablespoons of boiling water. Set aside to infuse.
Add the oil to a large heavy based heatproof casserole dish and set over a medium-high heat. When it is hot, add the chorizo, onions and peppers and fry together for 10 minutes, stirring frequently.
Reduce the heat a little before stirring through the smoked paprika and rice. Fry for another minute or two making sure all the rice grains are well coated in the juices in the pan. Pour in the stock, saffron and wine, and season with salt and freshly ground black pepper, stirring well and making sure the rice is completely submerged. Cover with a tight fitting lid or snuggly tucked piece of foil and bake in the oven for 25 minutes.
Remove, stir through the chicken, prawns and peas and most of the parsley, recover and return to the oven for a further 10 minutes. Serve immediately, with a little extra parsley scattered on top and lemon wedges to squeeze over.