Blanch the asparagus in boiling water for 2 minutes
Cut each mozzarella slice in half and sit both pieces on top of 2 spears of asparagus. Top with 2 more spears then wrap the asparagus in prosciutto so the mozzarella is enclosed (you will need 2 or 3 strips).
Heat a little olive oil in a pan, then carefully fry the parcels until the prosciutto has crisped and the mozzarella oozes.
Whisk together the olive oil and vinegar and add the basil.
Serve each parcel with salad leaves and a little dressing drizzled over.