For the pickled pork roast, coarsely chop onion and greens, add remaining ingredients and bring to a boil briefly. Leave to cool and pickle the pork roast in it for 5-7 days.
Cover and turn over frequently. Then strain the juice, add some marinade and roast at 180 degrees for 2 1/2 hours, basting several times with juice.
Then season the juice and bind.