Preheat oven to 450 degrees and place a baking sheet or pizza stone in the oven as it is heating up.
Brush a large piece of parchment paper with olive oil (big enough to fit your pizza stone or baking sheet.)
Place the cauliflower in a food processor fitted with a metal blade. Pulse for about 30 seconds until you get very small pieces (resembling snow or rice.) You should end up with about 3 cups of cauliflower.
Place the cauliflower and 2 cups of water in a medium saucepan and bring to a boil, lower the heat to a simmer, cover, and allow to steam for about 5 minutes, or until the cauliflower is tender. Drain in a fine mesh sieve and allow to cool. (If you use a colander to drain, you will lose a lot of cauliflower.)
When the cauliflower is cool enough to handle, wrap it all up in a clean, thin dish towel and squeeze out as much excess water as possible. The less moist the cauliflower, the crispier the crust will be.
Transfer the squeezed cauliflower to a bowl and stir in the parmesan or pecorino, mozzarella, salt, dried oregano, garlic powder, red pepper flakes and almond meal/flour. Add egg whites and mix with your hands until combined.
Using your hands, form the mixture into tightly packed 3” rounds or a 10-12” round and place them on the oiled parchment paper.
Slide the parchment paper onto the HOT baking sheet or pizza stone. An inverted baking sheet or a pizza peel can help with this.
Bake for approximately 15 minutes until the crust starts to turn golden brown.
Remove crusts from oven and top with desired toppings, then place back in the oven and cook for another 7 minutes until cheese is melted and bubbly. You just don’t want to overdo it with any toppings that are very wet.
Allow to cool slightly and serve.
Notes
You can bake the crusts earlier in the day and refrigerate them until ready to top and bake. Or you can make the batter the night before.