Tear the chicory into bite-size pieces. Place in a large salad bowl, cover with paper toweling, and refrigerate.

Peel the pear and cut into ½-inch cubes. Place the cubes in a small bowl and toss with the lemon juice. Set aside.

In a small skillet over medium heat, cook the bacon until crisp and golden, about 5 minutes. Drain the bacon on paper toweling. Discard the bacon fat and wipe off the skillet. Add the walnuts to the skillet and toast over low heat, stirring often, just until they begin to give off their oil, about 2 minutes. Remove from the heat and set aside.

Prepare the dressing: In a small bowl, whisk the salt, vinegar, and mustard with the pepper. Gradually add the oil and whisk until emulsified. Set aside.

Pour the dressing over the chicory and toss to coat. Divide the salad among 4 plates and sprinkle with the bacon, pear, walnuts, and Roquefort cheese.