For the dough, clean the cauliflower and broccoli, cut the florets from the stalk and wash them. Peel and chop the broccoli stalk. Cut the vegetables smaller and chop them finely in portions in the universal chopper. Grate cheese roughly. Mix cabbage mixture, half cheese and 2 eggs. Season with salt.
Press the vegetable mixture onto a deep baking tray (approx. 25 x 32 cm) lined with baking paper to form a flat base, pressing the edge upwards. Pre-bake in a pre-heated oven (electric cooker: 200 °C/circulating air: 180 °C/gas: see manufacturer) for approx. 25 minutes.
For the topping, peel and wash the parsnips and carrots and cut them lengthwise into halves or quarters. Heat the oil in a large pan. Sauté the vegetables in it, season with salt and pepper. Deglaze with 250 ml water. Cover and cook for about 8 minutes. Drain.
Whisk 4 eggs, sour cream and the rest of the cheese. Season with salt and pepper. Approx. 1⁄3 Spread the icing on the dough base. Add vegetables and pour the rest of the mixture over the dough. Bake at the same temperature for about 30 minutes.