Season pork neck with salt and pepper. Place in a roasting pan with quartered onion (1), coarsely chopped beetroot and a small amount of tap water. Roast for a total of about 1 1/2 hours at 200 degrees (gas: level 3). Turn the meat to the other side from time to time, brushing it a few times with the roasting liquid. Add a little tap water only when the pan starts to brown.
Scrape the young carrots, chop the greens to 2 cm. Peel the remaining onion (2), chop and steam with the carrots in butter or possibly light butter, season with salt and sugar and sauté in a little tap water until just fork-tender.
Bake the potato dumplings according to the package instructions.
Spread the apricot jam, if chunky, through a sieve, then mix with horseradish. Brush the roast all around with it and let it brown for 5 to 10 minutes. Pass the sauce through a sieve and season. Serve the roast with potato dumplings and carrots.