Preheat the oven to 220°C / 425°F / Gas mark 7.
Line 2 baking trays with greaseproof paper and set aside.
Roughly chop the cauliflower, removing all the leaves.
Place the cauliflower in the food processor and pulse 8-10 times until it is finely grated.
Place the cauliflower in a lidded dish and microwave for 10 minutes.
In a large bowl, mix the cauliflower, egg and cheese until combined.
Add the oregano, garlic and salt and mix until well.
Place half of the mixture on each tray and pat into a round shape that is around 1cm thick.
Bake for around 15-20 minutes or until the base is golden.
Add your favourite pizza toppings (in this case we used mushrooms) and return to the oven just until the cheese is melted.