Peel the kohlrabi, hollow it out with a ball cutter and cook it in boiling salted water for about 15 minutes. Take out and let drain
Peel and finely dice the onion, finely chop 50 g of the hollowed kohlrabi mass. Wash and drain the spinach leaves. Heat 2 tablespoons of oil in a frying pan, fry the minced meat until crumbly, remove. Heat 1 tablespoon of oil in a saucepan. Sauté onion and chopped kohlrabi in it until translucent. Add the spinach and let it collapse at medium heat. Dice the cheese finely. Mix stock and tomato paste. Mix spinach mixture, cheese cubes and stock with the minced meat, season with salt and pepper
Put the kohlrabis in a casserole dish, fill with minced meat and bake in a preheated oven (electric range: 200 °C/ convection oven: 175 °C/ gas: level 3) for 10-15 minutes