Place the arugula in a bowl. Quarter the pear lengthwise and remove the core. Cut into quarters and then in half again. Dress the pear with the juice of 1/2 lemon, thyme leaves, EVOO, salt and pepper. Place a few leaves of dressed greens on each slice of prosciutto with a slice of pear and roll up into a tight bundle. Cut each bundle in half, to make 16 pieces.