Peel the onions. Cut off a "lid" from the top of each onion. Hollow out onions with a ball cutter, leaving the 2 outer layers intact. Cut or chop the lid into fine cubes. Use the inner onion meat for other purposes
Pour 400 ml stock into a wide pot and fill up with water so that the liquid is about 2 cm high. Put the onions into the pot and cook covered for about 10 minutes. Peel, wash and chop the potatoes. Boil potatoes in salted water for about 20 minutes until soft
Drain the onions and collect the stock. Rinse onions briefly under cold water. Mix 75 ml onion stock, 100 ml broth and bread spread and season with salt and pepper. Bring the milk to the boil, remove from the heat and melt the butter in it. Grate cheese
l in a frying pan. Brown the mince in it for about 5 minutes until coarsely crumbly, season with salt and pepper. After about 2 minutes add onion cubes. Stir in tomato paste and roast for about 1 minute. Deglaze with approx. 2 tbsp. onion stock or water and simmer until the liquid has evaporated
Drain the potatoes. Add the milk mixture to the potatoes and mash to puree. Season to taste with salt and nutmeg. Loosely mix the mince and mashed potatoes and fill the onions with it. Put the onions in an ovenproof dish and sprinkle with cheese. Pour on the sauce and bake in a preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for approx. 20 minutes
Wash the parsley, shake dry and chop the leaves. Remove onions from the oven and sprinkle with chopped parsley before serving