In a small bowl, whisk together the soy sauce, honey, garlic, ginger, and cornstarch. Set aside.
Add the sesame oil to a large deep skillet over medium-high heat. Add the beef and onion and cook, stirring occasionally, until the meat is just about cooked through, about 5 minutes.
Pour in the reserved sauce, stir to combine, and cook for 1 minute. Add the broccoli and cook for 1 more minute.
Divide mixture evenly among 4 plates or shallow bowls, layering rice first, if using.
Top each with sesame seeds and scallions.
Video
Notes
* To blanch the broccoli- bring a big pot of water to boil. Drop the florets into the water and cook for two to three minutes until bright green and crisp-tender. Immediately drain in a colander and put in an ice bath (a large bowl filled with ice water), which will stop the cooking process. Once the broccoli is cool, drain in the colander again.