Preheat oven to 450 degrees. Bring water to a boil for the pasta. While this is coming to a boil, Trim and discard coarse leaves and tough stem roots from broccoli rabe. Peel large stems and cut stems and leaves into 1 1/2-inch pieces. Rinse and drain. Set garlic in a baking pan and broil or roast for 10 minutes or until outside begins to soften and get golden. Add pasta to boiling water. Heat olive oil in a large skillet. When hot add roasted garlic, broccoli rabe, broth, dried red pepper flakes and salt. Partially cover skillet and saute about 3 minutes. Add cannellini beans and cook, stirring occasionally, until broccoli is just tender and beans are heated through.
Drain pasta, transfer to serving bowl and toss with broccoli rabe and beans. Shave Parmesan slices over the top.