Preheat oven to 425 degrees.
Line 2 baking sheets with parchment paper.
Cut cauliflower into bite size pieces steam for 20 minutes until just tender. You can also use all ready riced frozen cauliflower and microwave for 8 minutes .
If using fresh, place cauliflower in food processor and pulse until the size of rice.
Place cooked but cooled cauliflower into a clean dry towel over a bowl and wring out as much liquid as you can.
Pour riced cauliflower into a large bowl and add Parmesan cheese, egg, seasonings and 1/2 cup mozzarella cheese.
Mix well then spread mixture onto baking sheet in a rectangular 8 by 10 shape. Bake for 10-15 minutes until browned on top.
Invert over onto the other baking sheet with parchment paper.
Sprinkle mozzarella over the top and bake another 5-10 minutes until browned.
Let rest 10 minutes. Slice into 24 pieces.