Preheat the oven to 160°C (approximately 320°F).
Peel the onions, carrots, celery and garlic and cut everything into cubes. Rinse the lamb, pat dry and season with salt and pepper. Sear the lamb on all sides in hot oil in a roasting pan. Remove from the pan and fry the vegetables in it until brown. Add the port, stock, a little red wine, cinnamon and star anise. Add the lamb back in. Simmer for 2.5 hours in the oven. Add more red wine as needed and turn the lamb regularly.
Remove the lamb from the sauce, simmer the sauce and season with salt and pepper.
Serve together. Goes well with pickled lemon and saffron rice.