Preheat oven to 450°. Grease a 14-in. pizza pan; sprinkle with cornmeal. On a floured surface, roll dough into a 13-in. circle. Transfer to prepared pan; build up edges slightly. Sprinkle with cheese, chicken and bacon. Bake until crust is lightly browned, 10-12 minutes.
Meanwhile, place romaine and arugula in a large bowl. In a small bowl, combine mayonnaise, lemon juice, lemon zest and pepper. Pour over lettuces; toss to coat. Arrange over warm pizza. Top with tomato, avocado and basil. Serve immediately.