Preheat oven to 425° F.
Grease cookie sheet with butter or coconut oil.
Grate the cauliflower with a cheese grater, then place cauliflower in water in a stainless steel pan and cook for 12 minutes. Drain.
Mix together the grated cauliflower, egg, and half of the cheese.
Transfer to the cookie sheet, and using your hands, pat out into a round about ¼″ thick.
Brush olive oil over top of crust. Bake for 15 minutes. While baking, mix tomato sauce, garlic, italian seasoning and sea salt.
Remove crust from the oven, then add tomato sauce, remaining cheese, mushrooms, and olives (or any other toppings).
Return to oven for 5–10 minutes, just until cheese is melted (extra veggies may add time to baking).