Cook broccoli florets in a steamer, remove while firm but bright green; don’t overcook. Place in cold water bath with ice cubes and drain once broccoli is cold.
Make the creamy dressing: In a small bowl, combine the vegan mayo, sugar and vinegar. Mix until well combined.
In a separate medium mixing bowl, combine the drained, cooled broccoli, grapes and celery. Add the creamy dressing and mix well. Cover and refrigerate for at least 4 hours, or overnight.
Before serving add the freshly diced green onion. Option to add cooked, crumbled bacon at this point too.