Take a large pot of salty water and bring it to a boil. Cook broccoli rabe in water for 3 to 5 minutes until tender and bright green. Drain well in a colander and set aside.
In a large saute pan heat a 2 count of extra-virgin olive oil over medium heat. Add the red pepper flakes and garlic, then toss in the broccoli rabe. Season with salt and pepper and cook for 2 to 3 minutes, gently tossing it in the pan. Finish with the lemon zest and juice and toss to combine. The broccoli rabe should be tender and fragrant with lemon when done. Give it one final taste and season, if necessary. Serve immediately.