Special equipment: six 6-inch wooden skewers
Whisk together the vinegar, maple syrup, Dijon and salt in a medium mixing bowl. While whisking, slowly drizzle in the olive oil. Set the dressing aside.
Cut the pears crosswise into 3 even pieces each (bottom, middle and top). Run the tip of a paring knife around the cores and remove, but leave the stems in place.
In a large mixing bowl, lightly toss the arugula, pomegranate seeds and walnuts together along with just enough dressing to coat; be gentle to avoid bruising the arugula. Add the goat cheese and toss lightly.
Build the stacked salads: Top each pear bottom with about 1/2 cup salad and then add the middle pear slice. Anchor the layers with a 6-inch wooden skewer. Add another 1/2 cup salad and top with the stem end of the pear. Trim the skewer so that it is flush with the pear and well concealed. Serve immediately.