Bring a pan full of water to the boil, add a good handful of salt, followed by the linguine, and cook at a good rolling boil for about 5 minutes, until just tender.
In a frying pan, heat a glug of olive oil. Add the garlic if using and cook for about 30 seconds. Add the chopped chilli and cook for about 10 seconds.
Add the prawns and cook until they have just turned.
Drain the pasta, reserving a tablespoon of the cooking water. Add this to the frying pan, together with the cooked linguine and the lemon juice if using. Add the rocket to the pan and cover. Turn the heat off and leave for a few minutes.
Stir everything together and season to taste.
You can also do a vegetarian version of this with roasted cubes of butternut squash instead of the prawns.
*Inspired by Joanna M. featured in the Realfood Cookbook