Crumble the yeast in your hands and dissolve it in a cup with sugar and warm water. Set aside for 15 minutes. Add 2 teaspoons of rice flour and 2 teaspoons of oat flour, stir to combine. Set aside for another 30 minutes.

Sift the rest of the flours into a large bowl, add salt. Gradually add water with dissolved yeast, mixing with a wooden spoon. Add 2 tablespoons of olive oil and mix it in the dough.

Transfer the dough to a lightly floured work surface. Knead for a few minutes until smooth and elastic. Transfer back to the bowl, cover and let rise for about 1 hour, until it has doubled in volume.

Meanwhile, cut the cauliflower into small florets and remove the outer leaves. Cover the florets with boiling water and set over medium heat, cook for 2 minutes. Drain and set aside on a strainer.

Preheat the oven to 450°F.

When the dough has doubled in volume, roll it out or stretch it in your hands to form a rectangle of approximately 8 x 11-inches. Form a higher rim around the edges. Place the pizza dough on a baking sheet lined with parchment paper.

Spread tomato passata over the dough, sprinkle with minced crushed garlic and season with black pepper. Add the tomatoes and the prepared cauliflower florets, transfer to the preheated oven. Bake the pizza for about 20-25 minutes, until the edges are lightly browned (ideally using convection setting).

Remove from the oven. Sprinkle generously with red onion slices, arugula, baby spinach, lamb's lettuce, and fresh oregano. Drizzle with the remaining olive oil. Serve hot.