Czech Koprova (Dill Soup)

3 medium-sized potatoes, cubed
2 Tablespoons chopped onion
3 cups water
1 teaspoon salt
2 cups fresh or canned green beans, optional
1 cup sour cream
2 ½ Tablespoons flour
3 eggs
Fresh dill
Vinegar

Boil the potatoes and onions in the 3 cups of water with 1 teaspoon salt till almost done. Add the green beans, if desired. Mix the 2 ½ Tablespoons flour in the sour cream and slowly stir into the potato mixture. When soup comes to a boil, add 1 to 3 Tablespoons chopped fresh dill (according to taste). Break the eggs, one at a time, in a cup, stir slightly, and add to the simmering soup. Cook over low heat until eggs are cooked. (1 to 2 teaspoons vinegar may be mixed into the soup for added zest). Serves 4