Green beans are full of vitamins and minerals and are not very expensive. They appear often on menus and at family dinners but usually are soggy and bland. There are not much vitamins left in them.
Green beans, like pasta, need lots of boiling water and then a short boiling time.
Putting the beans in some water with salt, heating to boiling point and cooking for several minutes is a recipe for grey beans without taste. Generations of school children ate those in the canteen. Many an office cafeteria will serve them that way as well.