The first bit is the tricky bit. Deshell and remove the heads but keep as you will be needing them later.
Carefully slice along the outer length of the prawn and remove the thin dark vein which is visible.
Add 2 teaspoons of olive oil to a pan over a medium heat and fry the prawn heads and shells. The natural oils from the shell and heads will be released.
Add the chopped plum tomato with the fennel and olive oil to the pan and bring to a simmer for about 5 minutes. When fully mixed, remove from the heat and pour through a sieve into a warmed bowl. I use the back of a ladle to push the goodness through the sieve. You don't want the shell to go through the sieve.
Place a pan of water over a high heat and bring to the boil. Add the pasta and cook according to the instructions.
When the pasta is cooked, drizzle a little of the prawn oil you have just made over the pasta and mix. It will add a lovely flavour to the pasta.
In a frying pan, add a little oil over a medium heat. when hot, add the prawns and fry gently until cooked. Normally about minutes.
In a large pre warmed serving dish, add the pasta and the prawns together with the tarragon and chives and parsley.
Serve immediately while piping hot.
I finely slice red chilli and place in a small bowl for hose who like the extra kick.