Most lupine beans should be treated, in order to neutralize the alkaloid substances that make them bitter:
1. Cover 2 cups (500 ml) of lupine beans with 6 cups (1.5 l) of cold water, then leave them to soak 12 hr.
2. Drain the lupine beans, rinse and cover them again with fresh water.
3. Cook the lupine beans gently until tender (about 2 hr). Check for doneness by inserting the point of a knife.
4. Drain the lupine beans, cover them again with cold water and let them cool completely.
5. Drain again, cover them once again with cold water, mix in 2 tablespoons (30 ml) of salt and place in a cool spot (not in the fridge). Leave to soak 6-7 days, changing the salted water twice a day.
6. Once the bitterness is gone, keep the lupine beans in the fridge in salted water in an airtight container.
7. To serve the lupine beans, drain the amount needed and serve as is or dressed with lemon juice, with or without their skin.
http://www.globalgourmet.com/food/cookbook/2009/visual-food-guide/lupine-bean.html#axzz3OE9KarsM