Peel the potatoes and cut into small pieces. Peel the carrots and cut into slices. Peel the kohlrabi and cut into pieces. Wash the beans and cut into pieces approx. 2 cm long.
Cook everything in 1.5 liters of water and the soup cubes for about 20-30 minutes, until the vegetables are soft.
Melt the butter in a saucepan and create a burn-in with the flour. Then add to the vegetables and bring to the boil. Season to taste with salt and pepper.