Clean, peel and wash the kohlrabi. Then hollow out the kohlrabi in the middle using a ball cutter. Put aside the kohlrabi scraps. Cook the hollowed kohlrabi in boiling salted water covered for 15-20 minutes.
Meanwhile wash parsley, dab dry, remove leaves and cut finely. Roast the pine nuts in a pan without fat, take them out and let them cool down. Peel shallots and garlic and dice finely. Heat butter in a pot. Sauté shallots and garlic in it. Deglaze with 75 ml water, stir in portions of spinach and let them collapse. Season with salt, pepper and nutmeg. Pour the spinach into a bowl. Coarsely chop the pine nuts, crumble the feta. Fold the feta, 150 g sour cream and pine nuts into the spinach and season with salt and pepper. Take out the kohlrabi, drain and collect the vegetable water
Fill the kohlrabi with the spinach mixture and place in an ovenproof dish. For the sauce, measure 300 ml vegetable water and bring to the boil. Add the kohlrabi scraps and cook for 5-10 minutes, stirring occasionally. Add 100 g sour cream, finely puree the sauce and season to taste with salt, pepper and nutmeg. Stir parsley into the sauce, except for a little bit for sprinkling. Pour the sauce around the stuffed kohlrabi and bake in the preheated oven (electric cooker: 200 °C/ gas: level 3) for about 15 minutes