This was a favorite snack growing up; we’d buy it from the cart vendors in the street and munch on them , leaving the skin aside. Apparently these beans were favored by the Romans and since we had to contend with the Romans for a few centuries, that would explain why we are still eating them in Lebanon as part of a mezze table, often with a glass of arak. (arak is our national drink and its taste is similar to ouzo and pastis)
Lupini beans are sold in middle-eastern stores brined in jars. I would soak these in water a couple of times before consumption; they can also be prepared from dried beans.
If you are preparing them from dried beans, you should soak them for 24 hours then drain them; cook them for two hours or longer until tender.
Then, soak them in cold water for 5 days, changing the water every day, until they are not bitter-tasting.
Add salt, and serve as a snack or part of a mezze.