Preheat your oven to 425°F (218°C) and line a baking sheet with parchment paper.
Break the cauliflower into florets and pulse in a food processor until it reaches a rice-like texture.
Transfer the cauliflower rice to a microwave-safe bowl, cover, and microwave on high for 5-6 minutes until soft. Let it cool slightly.
Place the cooked cauliflower in a clean kitchen towel and squeeze out as much moisture as possible.
In a bowl, combine the drained cauliflower with the egg whites, a pinch of salt, and dried oregano. Mix well until the mixture binds together.
Spread the cauliflower mixture onto the prepared baking sheet, pressing it into a thin, even round to form your crust.
Bake the crust in the preheated oven for 15 minutes or until it starts to crisp and turn lightly golden.
Remove the crust from the oven. Spread the tomato sauce evenly over the crust, then distribute sliced fresh mozzarella on top.
Drizzle with olive oil and season with a little extra salt and pepper.
Return the pizza to the oven and bake for an additional 8-10 minutes, until the cheese softens and begins to melt.
Garnish with fresh basil leaves, slice, and serve immediately.