For the dressing:
In a small bowl, whisk all dressing ingredients except the oil until well combined. Add the oil in a slow stream, whisking continuously. Place greens in a large bowl. Just before serving, toss with dressing and top with walnuts, cheese, and pears. *To toast walnuts, preheat oven to 350°F. Spread nuts on baking sheet and broil for about five to eight minutes, taking care not to burn them. Remove, turn over nuts, repeat. Remove and let cool before adding to other ingredients.