Mix the cooled pasta with the crumbled bacon, chopped lettuce, and diced tomatoes. Toss everything with a creamy mayonnaise dressing. Let it chill before serving to allow the flavors to come together.
Pour mayonnaise mixture over pasta mixture; toss lightly then serve immediately. If you're not serving this salad immediately, you may want to wait to add the pears and walnuts just before serving, so ...