Bring a large pot of water to a boil. While you are waiting for it to boil, cut the two heads of broccoli into small bite-sized florets.
Once the water is boiling, add the broccoli and leave to cook for exactly 1 minute. Do not cook longer than one minute, or the broccoli will turn mushy.
After 1 minute, remove the broccoli and place them in a bowl filled with ice and water. Once the broccoli is cool, drain and place in a large bowl.
In your serving bowl, combine the broccoli florets, scallions, toasted cashews, and sesame seeds.
Add the desired amount of dressing, toss, and serve.