Defrost the prawns if necessary. Peel and finely chop the onion. Clean, wash and grate the zucchini. Squeeze vigorously in a clean dishcloth or gauze cloth and place in a bowl. Add half the diced onion and egg, mix well. Season with salt and pepper, knead very well with chickpea flour.
Cover a tray with baking paper and preheat the oven (electric oven: 200 °C/circulating air: 180 °C/gas: see manufacturer). Halve the zucchini mixture and press it onto the baking tray as 2 trays (each 18-19 cm Ø). Bake in a hot oven for approx. 25 minutes.
Peel and chop the garlic. Heat 1 tablespoon of oil in a saucepan, sauté the rest of the onions and half the garlic. Add the chopped tomatoes and tomato paste and bring to the boil. Season with Italian herbs, salt and pepper and simmer for about 15 minutes.
Rinse shrimps cold and pat dry. Heat 2 tablespoons of olive oil in a frying pan, fry the prawns and remaining garlic for about 2 minutes, turning them over. Season with salt and pepper. Drain the mozzarella and cut into cubes.
When the zucchini bases are lightly browned and crisp, remove the tray and spread tomato sauce on top. Spread prawns and mozzarella on top and bake for another 10 minutes. Sort the spinach, wash and drain well and sprinkle on the finished pizzas. Halve the pizzas and serve immediately.