Place peppercorns, coriander, juniper berries and salt in a mortar and pound to a paste-like consistency. Rub the meat with it.
Melt the lard in a roasting pan and brown the roast all over. Cut the onion in half, add it to the meat in the roasting pan with the cut side down and fry it.
Then pour in about 500 ml of water and add the bay leaves and a few cloves of garlic. Now cover the roaster and put it in the oven on the lowest rack.
Roast for about 2 hours, checking every now and then if you need to add more water.
The roast is ready after three hours and should rest for about a quarter of an hour before cutting. In the meantime, bring the gravy to the boil and cook it off. Season if necessary, thicken with cornstarch if desired.