Bring about 2 quarts of water to a rolling boil. Then add the green beans to the boiling water and cook for 5 to 7 minutes. Remove from the boiling water and place in a bowl of ice water, or rinse immediately with ice-cold water.
Meanwhile, melt the butter and saute the mushrooms until tender, about 7 to 8 minutes. Add the green beans, milk, soup, Worcestershire sauce, Stone House Seasoning, and half of the crispy onions.