Heat a large paella pan over a medium heat and then add a drop of olive oil followed by the chorizo. Leave to crisp for about 5 minutes and then follow with the onions, garlic, and piquillos and cook for a further 10 minutes. Stir in the rice and season with salt and pepper and add in the paprika and saffron followed by the hot fish stock and leave to simmer for about 15 minutes. Scatter the pieces of monkfish over the rice and push under the surface with the back of a spoon. Then lay the mussels and prawns over the top and simmer for about 10 minutes, covered.
Once the mussels have opened the paella is ready. Serve with lemon wedges around the pan.