Prepare a large bowl of ice water, and set aside. Fill a large pot with water, salt heavily (it should taste like seawater), and bring to a boil. Add broccoli spigarello, and blanch until bright green and tender, about 2 minutes. Drain, immediately plunge into ice water until cooled, and drain again.
In a medium saucepan over medium-low heat, heat olive oil until shimmering. Add garlic, cover, and cook until tender but not browned, about 1 minute. Add broccoli spigarello and chili flakes. Stir slowly to gently reheat. Serve hot with, if desired, gnocchi or risotto.