Place pear halves, cut side up, on a baking sheet and brush them with honey. Place pan in oven. Bake for 15 to 20 minutes or until golden. Slice the pears lengthwise into half-inch slices. In a small bowl, whisk together the vinegar and shallots. Whisk in olive oil until emulsified. Add salt and pepper to taste. Toss the arugula with the vinaigrette. Plate salad individually with pear slices and toasted walnuts sprinkled on top.