Wash the potatoes thoroughly, dab dry, coat with oil, sprinkle with some caraway seeds and wrap in aluminium foil. Bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 1 1/4 hours.
Meanwhile, wash the beetroot and cook in plenty of boiling water for 25-30 minutes. Rinse under cold water and remove the skin. Let the beetroot cool down a little. Clean and wash spring onions and cut into rings.
Wash the apple, quarter it and remove the core. Dice apple and beetroot. Stir the apple, beetroot and spring onions into the sour cream. Stir creamy with the milk and season to taste with salt and pepper.
Finely chop the dill, except for something to garnish. Wrap the potatoes out of the foil, cut them crosswise and press them together. Fill the sauce onto the broken potato. Serve sprinkled with dill.