Put potato buffer powder in a bowl and add 450 ml cold water. Mix well with a whisk. Clean the zucchini (only cut off the ends), wash and roughly grate.
Peel and finely chop the onion. Wash the chives, dab dry and cut into fine rolls. Stir half of the onion and zucchini into the potato pancake mixture. Heat the oil in portions in a large pan and bake 3 buffers on each side for 2-3 minutes at medium heat.
Keep warm. In the meantime, mix yoghurt, sour cream, remaining onion and 3/4 of the chives. Season with salt and pepper. Skip the bacon in a second pan. Arrange 3 buffers, a blob of yoghurt sour cream and bacon on each plate.
Sprinkle with remaining chives and serve garnished with tomatoes and chives as desired. Add the remaining yoghurt sour cream.