Put the haricot beans in a large
bowl and cover with cold water.
Leave overnight or for at least 5
hours to soak.
Drain the beans and transfer to a
saucepan.
Cover with fresh water and bring
to the boil.
Skim off any scum and simmer for
60 minutes, or until tender.
Drain and set aside.
Heat the olive oil in a large
saucepan.
Add the carrots, leeks, celery and
tomatoes and fry over a low heat for 2 minutes, then add the water.
Bring to the boil, reduce the heat
immediately and simmer for 15 minutes.
Add the potatoes, French beans,
courgettes, vermicelli and the reserved haricot beans and simmer for
15-20 minutes, until the pasta and all the vegetables are tender.
Season to taste with salt and
pepper.
Meanwhile, make the pistou.
Put the garlic, salt and basil in
a food processor and process to a paste.
Add the Parmesan and, with the
motor running, pour in the olive oil in a thin trickle through the
feed tube until you have a thick green paste.
Stir into the soup just before
serving, or hand the pistou separately.