Wash the leg of lamb and pat dry. Rub the spices vigorously on all sides. Put the meat in a roaster with a little water. The meat side should be facing down.
Clean the vegetables, chop them roughly and spread them around the lamb. Put the roaster in the preheated oven (220 ° C) on the lowest level. Let the leg roast for 2 hours. Replace evaporated liquid again and again.
After 2 hours, turn the roast and reduce the temperature to 190 ° C. Leave the roast in the oven for another 2 hours.
At the end of the cooking time, remove the meat and let it rest for a while. In the meantime, boil the roast set with water and strain the vegetables through a sieve into the sauce. Season to taste with salt and pepper. Tie a little if necessary.
Bone the leg and cut the meat into slices. Reheat in the sauce.