Peel the carrots and top and tail them. Using a potato peeler, slice them into ribbons.
Top and tail the courgettes and using a potato peeler, slice them into ribbons.
Heat the oil in a wok or large, heavy frying pan. When very hot, add the carrots and stir fry for 1 minute. Add the courgettes and stir fry for a further 1 minute. Add the lemon juice and remove from the heat.
Stir in the rocket pesto and season well with salt and pepper.