Bring 1 inch of salted water to a boil in a large straight-sided skillet. Add broccoli rabe, and cook until bright green, 2 to 3 minutes.
Use a slotted spoon or tongs to remove broccoli rabe from pan. Drain water from skillet. Add oil (be careful as it may spatter), garlic, and pepper flakes, and heat briefly. Return broccoli rabe to pan, and cook, tossing to combine, about 1 minute. Serve hot or at room temperature.