To rice your cauliflower, take 1 large head of cauliflower, remove the stems and leaves, and chop the florets into chunks. Add to a food processor and pulse just until it looks like rice. Alternatively, you can grate the cauliflower with a cheese grater.
Place the riced cauliflower in a microwave safe bowl, add 1/4 cup water, and microwave for 6-8 minutes, stirring half-way through.
To make the pizza, preheat the oven to 450 degrees F. Spray a pizza pan or cookie sheet with non-stick cooking spray.
In a medium bowl, combine the cauliflower, mozzarella cheese and egg together and stir until well incorporated. Add the oregano, garlic, and garlic salt. Transfer to the cookie sheet, and shape into a 9-inch circle. Brush the crust with olive oil to help it brown in the oven.
Baked at 450 degrees F for 15 minutes, until the crust is browned and cooked through the middle.
Remove the crust from the oven, add your sauce and toppings. Place under a broiler at high heat until the cheese is melted and bubbly. (About 3-4 minutes).
Allow the pizza to cool slightly, then cut into slices and serve.