1) Fry the leeks to soften them, then the chorizo to get the juices flowing.
2) Add the rice, paprika and turmeric and mix it all up...wow, yellow rice!
3) Pour in the stock, cover with a lid and bring to the boil.
4) Let it simmer until the rice is almost cooked.
5) Mix in the prawns and tarragon and give it a final toss.