In a medium Dutch oven, combine the grappa, sugar, orange zest, salt, red pepper flakes, cloves, peppercorns, rosemary and 2 cups water. Bring to a simmer over medium heat, stirring occasionally with a wooden spoon to dissolve the sugar; cook for 5 minutes. Carefully place the pears halves, cut-side down, in the poaching liquid. Cover with a piece of parchment pressed directly to the surface of the liquid, and simmer gently for 10 to 12 minutes. Turn off the heat and allow the pears to cool in the liquid for 5 minutes. Then remove the pears with a slotted spoon to a plate to cool completely, about 15 minutes.
Cut each pear half into 4 wedges. Gather a few leaves of arugula and bundle them together with a pear wedge. Lay the bundle on one end of a piece of speck and roll up to enclose; secure with a toothpick. Repeat with the remaining pears, arugula and speck.