For the white cabbage lasagna, sauté the onion in the olive oil. Add the cabbage and carrots and sauté. Add the vegetable soup and let it steam briefly. In the meantime, prepare the roux. Add the cheese and pour over the cabbage mixture. Season to taste. Pour the cabbage mixture into a greased baking dish and alternate layers of vegetables, lasagna sheets and vegetables again. Sprinkle the white cabbage lasagna with plenty of cheese and bake in the preheated oven at 180°C degrees top and bottom heat for 30-40 minutes.