How to Make It
In a medium saucepan, cover the cranberry beans with 1 inch of water and bring to a boil. Reduce the heat to low, cover partially and simmer the beans until almost tender, about 20 minutes. Season with salt and cook until tender, about 5 minutes longer; drain.
Bundle the parsley stems, thyme sprigs and bay leaf in the slice of bacon and tie with kitchen string. Heat the olive oil in a medium saucepan. Add the onion and garlic and cook over low heat until softened, about 8 minutes. Add the carrot and celery and cook until softened, about 8 minutes. Add the cranberry beans, bacon bundle, stock, tomatoes and green beans and bring to a boil. Cover partially, reduce the heat to low and simmer for 10 minutes. Stir in the chopped parsley, lemon juice and lemon zest and season the soup with salt and pepper.
In a saucepan of boiling water, blanch the basil leaves for 5 seconds. Drain and rinse the basil under cold water. Squeeze dry and finely chop.
In a mortar, pound the garlic to a paste. Add the basil and pound together. Stir in the olive oil and season with salt and pepper.
Heat the olive oil in a large skillet. Add the bread and cook over moderate heat until starting to crisp, about 2 minutes. Add the parsley and cook, stirring, until the bread is browned and crisp, about 3 minutes longer. Season with salt and pepper and transfer to a plate.
Reheat the soup and discard the bacon bundle. Ladle the soup into bowls and drizzle with the pistou. Serve at once, passing the croutons at the table.
Any combination of fresh shell beans can be used. Cooking time will vary according to the variety of bean.