Melt 3 tablespoons butter in a large nonstick skillet over medium-high heat. Add pear slices to pan, and sprinkle with pepper. Cook 4 minutes or until golden brown. Set aside.
Melt remaining 2 tablespoons butter in same skillet over medium heat. Stir in walnuts, sugar, and 1 tablespoon water. Cook, stirring constantly, 2 minutes or until sugar melts and coats walnuts. Spoon onto wax paper, and let cool about 15 minutes.
Arrange lettuce and reserved pears on a serving platter. Sprinkle with walnuts and blue cheese. Serve with Pear Vinaigrette.