1.Add 1" Of Water To The Bottom Of A Medium Pot (With Lid). Insert Steamer Basket And Fill With Chopped Cauliflower. Cover. 2.Steam Cauliflower On The Stove Top Over Medium-High Heat Until Slightly Tender, About 10 Minutes After Water Begins To Simmer (Overcooking Will Develop A Stronger "Cauliflower" Smell, And A Mushy Texture). 3.Drain Cauliflower And Rinse With Cold Water To Cool Immediately. Place In A Large Bowl 4.Add Celery, Onion, Parsley, And Egg. 5.Stir In Mayonnaise, Dijon Mustard, And Sea Salt (If Desired). 6.Serve Immediately Or Store In Refrigerator.