First cut the two onions into small cubes and sweat in a little oil until translucent. While the kohlrabi cut into cubes is being added to the onions, the bacon must be fried separately.
Add the vegetable stock to the onions and kohlrabi and simmer over a low heat. When the kohlrabi is done but still has a bite to it, take the pot off the heat.
Now the whole thing is processed into a creamy soup with the hand blender. Stir in the sour cream and cheese and season with salt and pepper.