Dice the onions and fry them with the meat. Shape the mince into small balls and fry them too.
First layer the meat, then the meatballs in a roasting pan, pour peach halves or slices over them. Pour juice from a can over it, sprinkle with ketchup and sambal oelek.
Cover and cook in the oven at 200 degrees for 2 hours. Do not open the roaster when doing this.