If you want to make a delicious soup, do NOT add dried Lupini beans.
These beans are INSANELY bitter and will ruin your entire soup!!!!!!
Apparently these beans have a very high alkaloid content and this will leech into your soup and make you want to vomit when you taste it. The wretched taste will then linger in your mouth for hours.
If you do wish to snack on Lupini beans after this warning, you can buy the canned pre-soaked ones. Otherwise you apparently have to soak these beans for ~5 days, changing the water often until all the bitterness is away. You may also have to cook and salt them.
I tell you this though. These 2-lips won't be getting near a Lupini again.