Peel and dice the onion. Wash and clean the cucumber, cut it in half lengthwise and cut into slices. Wash dill, shake dry and pluck dill flags from the stalks except for a little topping. Heat oil, add onion and sauté for about 6 minutes until translucent. After 3 minutes add cucumber and sweat it on. Fill up with broth and bring to the boil.
Season with salt, pepper and dill. Take out some cucumber as garnish. Finely puree the rest of the soup with a blender. Put the cucumber garnish back into the soup, let it cool down briefly and put it in a cool place. Garnish with dill for serving
1 hour waiting time