Peel all the vegetables. Cut the potatoes and cabbage into small cubes; wash the leeks carefully and slice them. Slice the carrots and celery as well and quarter the onions. You should have about ten cups of prepared vegetables. Use the same amount of water.

Place all the vegetables in a stockpot. Grind fresh pepper, add the salt, thyme, bay leaves, parsley and toss the vegetables in. Add water. Cover and bring to boil slowly, then simmer for 1 ½ hours.

Remove and discard the bay leaves then pour the vegetables and purée them in a food mill using the cooking liquid over the purée to thin it out. Reheat the soup until the first boil. Correct seasonings and serve.