Use a vegetable peeler to slice the courgettes into wide strips, discarding the central, seedy part. Heat the oil in a large frying pan, add the lemon zest and garlic, and fry over a medium heat for 1 min. Add the courgette strips and cook, stirring regularly, for a further 1-2 mins until the courgettes are slightly softened. Add a squeeze of lemon juice and toss the basil through.