Rinse raw broccoli and then place it in a strainer, submerge in boiling water to blanched for about 10 seconds, strain it as soon as it starts getting dark green. Run cold water over broccoli to stop cooking, strain, let cool and dry completely.
When the broccoli and celery have dried completely from rinsing, combine the first 5 ingredients in a large bowl.
Combine mayonnaise and remaining ingredients, stirring with a whisk. Pour dressing over broccoli mixture, and toss well. Chill for at least 1 hour, preferably 2 hours.