Favas

(Vicia faba)
Favas, called broad beans by the British, shouldn’t really be called a bean; more closely related to peas, they thrive in the same conditions peas favour – cool and damp. Plant in early spring, at the same time as peas; they will be happiest if you mulch them and water if it turns dry. Favas are upright plants which theoretically don’t need support. In fact, it has been pointed out that the story of Jack and the Beanstalk must be referring to a fava, rather than any of the Phaseolus beans, for two reasons:
first, no pole or string is mentioned for the bean to grow up (ha ha); and, more convincingly, the story apparently originates before the Europeans reached the Americas, where all Phaseolus beans are from.
Notwithstanding that piece of historical trivia, favas have weak stems and are prone to lodging (falling over) as they near maturity. To prevent this, drive in sticks around your patch and tie a string between their tops. Favas can be eaten as shelly beans, when the pods are turgid-looking but still green; or they can be left until the pods turn black and harvested as dry beans. I have heard that the very young pods and leaves are also edible, but have never tried eating them.
A little warning: a tiny percentage of humanity suffers an unpleasant allergy-like reaction, called favism, upon eating favas. This is so rare that I have never heard of an actual case of favism, but it is possible. Eat a small serving the first few times and pay attention to how you feel; if they have negative effects, stop eating them, but I don’t expect it.