2 onions, chopped
1 quart yellow wax beans cut into 1" pieces
1 pint sour cream
2 large potatoes, peeled and diced
Saute' onions with salt & pepper until onions are clear but not browned.
In a separate pot, cook potatoes in water (just enough to cover potatoes totally) until tender. Do NOT drain......add onions, beans and simmer.
In a bowl, mix sour cream and 1 heaping Tablespoon of flour. Add water until soupy and then add the mixture to the potato/bean soup.
In a small saucepan (or in the pot you cooked the onions in), melt 1/3 cube of butter and add I T of flour and brown. Add enough water to make a gravy (roux) and bring to a boil. Add 2 T cider vinegar and add all of this to the bean/potato mixture and cook until thickened.