Ingredients (Serves 6-8)
Peel the prawns and set the tails aside. Put the heads and shells into a large pan of water and simmer for 10 minutes. Remove from the heat and strain the liquid into a bowl.
If using mussels, remove the beards then scrub under cold running water. If using clams, scrub under cold running water.
Discard any shellfish with broken shells or which don’t shut when sharply tapped.
Put the shellfish in a saucepan or frying pan, add 50ml/2fl oz water, cover and cook over a high heat for 3-6 minutes, until the shells have opened. Lift out with a slotted spoon, discarding any that remain closed. Reserve the cooking liquid.
Shell the mussels and clams, reserving a few in shells for the garnish. Strain the cooking liquid through a muslin-lined sieve into the prawn stock. You need 1.75ltr/3pt, so make up with water, if necessary. Pour the stock into a saucepan and heat gently, but don’t allow to boil.
Preheat the oven to 180°C, 350°F, Gas 4. Cover the base of a paella pan (or large, heavy frying pan with a metal handle) with oil.
Add the onion and garlic and cook over a medium heat, stirring occasionally, for 7 minutes until lightly browned. Add the tomato or tomato sauce and cook, stirring, for a few minutes.
Reserve a few prawns for the garnish and add the remainder to the pan with the squid and rice.
Cook, stirring constantly, until the squid is opaque. Add the shelled mussels or clams, season with salt and pour in the stock.
Gently shake to ensure the liquid is evenly distributed.
Pound the parsley with the saffron, then stir in 2 tbsp water and add to the pan. Crumble in the stock cubes and gently stir with a wooden spoon. Add the peas and cook for a few minutes.
Garnish with red pepper, the reserved prawns and shellfish in the shell. Transfer to the oven and bake for 25 minutes. Serve with lemon wedges hung over the side of the pan.