Cut each bagel into 2 half-circles using a serrated knife. Cut each half-circle horizontally into 1/4-inch-thick slices. Place bagel slices on a baking sheet; coat with cooking spray. Bake at 300° for 25 minutes or until lightly browned and crisp; set aside.
Combine lettuce, cheese, and pepper in a large bowl; toss well. Combine lemon juice and next 4 ingredients, stirring well. Add yogurt; stir well. Add to lettuce mixture; toss gently to coat.
Break bagel chips into small pieces; add to lettuce mixture, and toss gently. Serve immediately.