Throw away any with broken shells. Pick through the shells, tapping each one on the side of the sink – they should be closed or should slowly close when tapped – if they stay open, throw them away.

If any of the shells still have barnacles or stringy beards attached, pull them off with a cutlery knife and rinse the shells well. Keep in the colander, covered with a cold, damp cloth, until you’re ready to cook.

2)Peel the prawn shells on the body section only – leave the heads and tails intact.

Score down the backs and pull out any gritty entrails.

Chill until you’re ready to cook.

3)Put the saffron in a small cup, cover with 50ml kettle-hot water and set aside for 10 mins.

If using vermicelli, put in a bowl and crush to little pieces (about 1cm long) with your hands.

Heat the oil in a large frying pan with at least a 3cm lip, or a 40cm paella pan.

Add the onion and stir around the pan for 5 mins until soft.

Add the garlic and cook for 1 min more, then tip in the vermicelli and cook for 5 mins, stirring from time to time, until the vermicelli is toasted brown.

Stir in the paprika.