First, boil the cauliflower well. Then drain the water well and put it in a blender. Add the eggs and oats to the blender and blend well until you get a homogeneous and thick mixture.
In another bowl, grate the onion finely, then add the mixture of cauliflower, eggs and oats, mix with a spoon and finally add the spices and oil. If the mixture is very liquid, add another 1-2 tablespoons of oats.
Lina some parchment paper in a standard baking pan on which you will sprinkle a little oil. Then pour the mixture and distribute it evenly. Be careful that the layer is not too thick.
Bake the prepared crust in a preheated oven at 450 F, for 10 minutes. After 10 minutes, take it out of the oven and start with the toppings on top.
First coat the pizza with the tomato puree, then chop the tomatoes on circles and arrange them on top, put the mushrooms on them and finally the grated mozzarella. Add a little salt and add fresh or dried basil. Return the pizza to the oven, but now lower the oven to 400 F and bake for another 20-25 minutes.