Begin by making the soup. Heat the olive oil in a large soup pot over moderate heat, and cook the onions and carrots for 5 to 10 minutes, until soft but not brown. Add the remaining ingredients and bring to a boil. Cover, reduce the heat, and simmer for 15 to 20 minutes, until the vegetables are tender.

For the pistou, combine all ingredients in a blender or food processor and puree until smooth.

To serve, ladle the soup into bowls and top with about 2 tablespoons (30 ml) of pistou and one (15 ml) of grated cheese. Served with thick slices of toasted garlic bread, this dish is a meal in itself.

Serves 4 to 6.