Bring a large pot of salted water to a boil. Blanch broccoli rabe for 2-3 minutes and quickly transfer to an ice-water bath. Remove the broccoli rabe from the bath and squeeze out excess water. Heat oil, garlic and red pepper flakes in a large skillet over medium-high heat. Add broccoli rabe and salt and saute for 2 minutes. Serve warm or at room temperature.