Cut thick, lower stems off broccoli rabe and peel. Reserve florets and leaves.
Heat a large skillet over medium-high heat. Add 1 tablespoon olive oil, garlic, and red pepper flakes; saute until fragrant, about 45 seconds. Add stems; saute until coated with oil, about 45 seconds. Pour in water; continue cooking until stems are mostly tender, 3 to 4 minutes. Stir in florets, leaves, and salt. Cover skillet and cook until tender, about 5 minutes.
Transfer broccoli rabe and its juices to a serving bowl. Top with remaining 1 tablespoon olive oil.
