For the tomato sauce, peel and finely dice the onion and garlic. Heat the oil in a pot. Fry the onion and garlic for about 5 minutes. Add chunky tomatoes, bring to the boil and simmer for about 5 minutes while stirring. Season to taste with salt, pepper, 1 pinch of sugar and oregano.
Clean the cauliflower, cut it into large florets from the stalk and wash it. Blanch in boiling salted water for about 4 minutes. Pour into a sieve and rinse with cold water.
Wash the tomatoes and cut them into slices. Clean and wash spring onions and cut into fine rings. Cut mozzarella into slices. Preheat oven (electric cooker: 225 °C/circulating air: 200 °C/gas: see manufacturer).
For the pizza bases, grate Gouda roughly. Coarsely grate the cauliflower. Mix Gouda and cabbage. Line two trays with baking paper. Halve the cauliflower mixture and spread it thinly on the trays to form a round pizza base (approx. 30 cm Ø each). Pre-bake in the hot oven for about 10 minutes one after the other.
Spread half of the tomato sauce, tomatoes, spring onions and mozzarella on the first base. Bake in a hot oven for about 12 minutes. In the meantime, cover the second base in the same way and finish baking.
Wash basil, shake dry, pluck off leaves and chop coarsely. Serve the cauliflower pizzas sprinkled with basil.