Pre heat oven to 220℃/ 200℃ (fan)/ 425F and line a baking sheet with parchment paper
Add the cauliflower florets to a food processor and pulse until they resemble rice or couscous. Alternatively, grate the cauliflower using a box grater or use pre-riced cauliflower.
Transfer the cauliflower to a large microwave-safe bowl, cover and microwave for 7 minutes, or until tender. Allow to cool until comfortable to handle.
Transfer the cooked cauliflower to a clean tea towel or cheesecloth and squeeze out as much liquid as possible. Continue squeezing until very little moisture remains. You may find it easier to do this in smaller batches.
Place the squeezed cauliflower into a large bowl. Add the cheddar, Parmesan, egg, Italian seasoning, salt and pepper, and mix until well combined.
Shape the pizza base(s). Mini pizzas: Divide the cauliflower mixture into 8 portions and shape into pizza bases approximately 10cm (4 inches) wide and ½ cm thick. A presentation ring helps create an even shape, but you can also shape them by hand. Large pizza: Shape the mixture into one large pizza base approximately 25–28cm (10–11 inches) wide, keeping the thickness even throughout. Bake the base(s).Mini pizzas: Bake for 15 minutes, carefully flip each base over, then bake for a further 5 minutes, or until golden brown.Large pizza: Bake for 20–25 minutes, carefully flip, then bake for a further 5–10 minutes, or until the base is golden and feels set. Add toppings. Spread each baked crust with a thin layer of pizza sauce. Top with mozzarella and your favourite toppings.
Return to the oven for 5–10 minutes, or until the cheese has melted and the toppings are cooked. Allow the pizzas to cool for 3–5 minutes before serving, this helps the base harden.