1. The thick skins of the beans would give a bitter taste to the soup; they would also give it a granulated appearance and a bad colour.
2. They must therefore be removed and this should be done with a small pointed knife.
3. Then cook the beans with the sprigs of savory quickly in boiling stock, with the lid off the pan, for 20 minutes.
4. When the beans are beginning to break, take off and drain, keeping the liquor and reserving a few of the best beans for the garnish.
5. Rub the rest of them through a fine sieve.
6. Return to the pan with the liquor. Bring to the boil, season, simmer 10-15 minutes, skimming frequently.
7. Mix the arrowroot with the milk, pour into the soup, and allow to boil up for a minute or two.
8. Then add the butter in small pieces, and the broad beans kept back for garnish.
A liaison of egg yolks may be added to the soup.