Saute the onions in the butter or oil until tender - about five minutes.
Drain half of the canning water out of your green beans.
Add the green beans and the remaining water to your onions.
Put the lid on your pot and simmer for about 20 minutes.
Enjoy!!
P.S. You do not have to saute the onions first. Drain your beans, put them into the pot with half of the water, add your onions, butter or oil and simmer for about 45 minutes. You'll get the same mouth watering dish either way!