Peel and clean the cucumbers, cut them in half lengthwise and remove the seeds. Cut the cucumbers into cubes. Peel and wash potatoes and cut into cubes. Cut sausage into thin slices. Heat oil in a pot and leave sausage crispy.
Add the potatoes and cucumbers, pour on the stock, bring to the boil and simmer for about 10 minutes. Wash and halve the tomatoes. Wash marjoram, shake dry and pluck leaves from the stalks. 2 minutes before the end of cooking add marjoram and tomatoes to the soup.
Season to taste with salt and pepper.