Heat the oil in a large saucepan, add the monkfish and squid and sauté gently until golden. Add the onion, tomatoes, paprika and garlic, and season to taste with salt and pepper. Cook, stirring, for 1-2 minutes.
Add the rice and stock, and bring to the boil. Simmer gently for 5 minutes without stirring.
Place the mussels and prawns on top of the rice and continue cooking for 15 minutes.
Discard any mussels that have not opened. Add the lobster or crab meat and cook for 5 minutes until all the liquid has been absorbed.
Stir the seafood into the rice, and serve immediately.