Preheat the oven to 220°C (approximately 430°F). Crush 1 teaspoon of salt, pepper, allspice, clove and marjoram in a mortar. Rub the meat well with the spice mixture. Rinse and coarsely chop the carrot, parsley and leek. Rinse the pork bones in cold water. Line the bottom of a roasting pan with the oil. Add the pork, chopped vegetables and bones to the pan. Cook on the middle rack for 15 minutes. Add the broth and beer and cook another 30 minutes. Turn the temperature down to 200°C (approximately 400°F) and cook 1 1/2 hours.
Remove the pan from the oven, remove the meat from the pan and cover it on a plate. Let it rest in the cooling oven for 15 minutes.
Meanwhile, drain the cooking liquid in a colander with the vegetables and bone, collecting the juices in a pot. Remove the bones. Press the vegetables through a sieve into the cooking liquid. Boil this sauce and season with salt and pepper. Cut the roast into slices and serve with the sauce.
Goes well with fries and a small salad.