To make the vinaigrette, whisk oil with vinegar in a non-reactive bowl. Season to taste with salt and pepper.
Combine the lettuces and pears in a large bowl. Add the vinaigrette and toss to evenly coat the ingredients. Scatter the nuts and cheese over the surface, toss again to distribute and serve immediately.
Bring 2 quarts water to a boil over high heat. Add walnuts and blanch 40 seconds. Remove pan from the heat and immediately drain the walnuts into a colander, shaking well to remove excess moisture.
In a large bowl, combine drained walnuts and sugar, stirring to evenly coat the nuts. Remove the nuts to a baking sheet lined with parchment paper and bake at 325 degrees F 8 to 10 minutes, or until until golden brown.
Makes 4 cups