Peel the carrots and cut into slices. Cut the cauliflower into small florets. Dice the celery bulb and cut the leek into rings. Bring the vegetables with the water to the boil, add the peeled ribs and let everything simmer for 2 hours on a low heat. Remove the peeled ribs and remove the bones, then cut into small cubes. Peel and dice the potatoes. Remove the stalk from the cabbage and cut into bite-sized pieces. Add the potatoes, white cabbage, ribs, Provence herbs, salt, pepper and vegetable stock and cook for another hour on a low heat.