Clean and chop the onion coarsely, wash and dry the shank. In a bowl, mix the spices with the olive oil and sugar. Rub this mixture into the meat.
Bake at 392°F (200 °C) for about 30 min. first, then reduce to 320°F (160 °C) and saute for 2 hours. Finally, take the lid off, check on the meat and leave it without it to crisp for another 20 min.