I have made this salad both with raw and blanched broccoli. I don't think there is much taste difference, so now I don't bother to blanch it. But if you really, really don't want to eat raw broccoli then put a big pot of salted water on the stove and bring it to a boil. Quickly dunk the chopped broccoli in the water and remove it after 1 minute with a slotted spoon. Let the broccoli drain and cool and proceed with the recipe.