Boil the potatoes for 40 minutes until tender, then drain and mash.
Add the egg and seasoning to a well in the center of the potatoes.
Mix in the flour and knead for 4 minutes until the dough is dry.
Roll the dough into 2cm diameter lengths and cut into 2cm intervals.
Boil gnocchi for 3 minutes until they float, then refresh in iced water.
Fry onions, carrots, celery, garlic, chilli, and pepper in oil until soft.
Stir in tomato purée and cook for 8 minutes until rich red.
Add red wine, stock, and rosemary, then bring to a boil.
Simmer the duck meat in the liquid for 60 minutes until tender.
Add gnocchi to the ragu and warm through.
Serve in bowls garnished with shaved Pecorino cheese.