Place the rocket in a bowl. Dress it with the juice of half a lemon, the thyme leaves, olive oil, salt and pepper.
Quarter the pear lengthwise and remove the core. Cut into quarters and then in half again.
Place a few leaves of dressed greens on each slice of prosciutto. Add a slice of pear and roll up the prosciutto into a tight bundle. Cut each bundle in half, to make 16 pieces.