Cut the beans into pieces about 1.5 cm in size. Chop the onions into small pieces. Dice the potatoes. Steam the onion until translucent, add the soup stock, bring to the boil, add the green beans and the potato cubes. Add bacon. Stir in vinegar essence and sugar and cook until the beans and potatoes are firm to the bite, about 10-20 minutes depending on the bean thickness.