Peel and coarsely chop the carrots, onions, leek and celery.
Melt the butter in a large saucepan and add the chopped
Saute for 1 minutes, stirring occasionally, until the
vegetables are soft.
Peel the potatoes and cut into small chunks. Put the potatoes, bouguet garni, stock, and salt and pepper into the saucepan with enough water to cover the vegetables.
Bring to the boil and simmer for 45 minutes.
Remove the bouquet garni and serve. The potatoes thicken the soup and may disappear into the liquid.
The vegetables may be diced or finely chopped, using a food
processor, if preferred.