Place 375 g (14 oz) French beans (the beans inside the pods to be large) cut in small pieces, in 1½ litres (2⅝ pt or 6½ U.S. cups) boiling water; add 500 g (1 lb 2 oz) potatoes cut in Paysanne, the roughly chopped flesh only of 2 tomatoes and 10 g (4 oz) salt.
When the vegetables are nearly cooked, add 180 g (6 oz) large vermicelli and finish cooking the soup very gently taking care that, as the soup is fairly thick, it does not stick to the bottom of the pan.
At the last moment pound together 2 small cloves of garlic, 4 g (4 oz) basil and the flesh only of 1 grilled tomato. Into this paste incorporate 2 tbs oil drop by drop then dilute it with 2 tbs of liquid from the soup.
Pour the soup into a tureen, add the Aillade prepared as above, and 75 g (2½ oz) grated fresh Gruyère cheese.