I saw a soul food recipe for butter beans (lima beans outside the south), mushrooms, and cream that reminded me of succotash a little, and so I added corn, with the idea that butter beans and corn were at their peak not far apart in the summer. You want the smallest possible light green colored butter beans for this. —TomFreeland
Start a pot of water boiling to have generous room for the butter beans. Salt the water (not a huge amount) and begin cooking the butter beans.
Put the cream in a saucepan and start it toward simmering. You are going to cook it to reduce by 2/3.
Cut the corn. If you're using a knife, set the cobs on end in a bowl and first cut the kernnels so they are cut in half, then cut them at their base, and scrape to get more juice into the bowl. This works better if you have a corn cutter.
In a small skillet, cook the mushrooms till they give up their liquid and get dry again and then set aside.
Cook the butter beans until just past crunchy toward soft--12-15 minutes, then drain them.
When the cream is reduced by half, add the mushrooms and keep simmering. About 4 minutes before the butterbeans are done, add the corn to the simmering cream.
When the corn is just cooked (you don't want to cook it much), add the butter beans and then stir together and taste and add salt and fresh ground black pepper to taste.