2) Put the sweet potato in a medium saucepan of salted cold water to cover and bring to the boil. Reduce the heat and simmer for about 6 minutes, until the potato is just tender. Drain and allow to cool enough to handle. Peel the potato and cut it into 0.5cm cubes.
3) Heat a medium frying pan over a medium-low heat. Add the duck legs skin side down and cook for about 10 to 12 minutes, until the fat has rendered and the duck is warm. Remove the duck to a plate.
4) If the skillet seems dry, add a little olive oil. Add the crushed garlic and rosemary and cook for about 3 minutes, until fragrant. Discard the rosemary and garlic.
5) Add the onion and cook for about 4 minutes, until tender. Add the celery and red pepper and cook for about 3 minutes, until tender. Season with 1.5 tsp of salt and some pepper. Add the chopped garlic and cook for about 2 minutes more.
6) Whilst the vegetables cook, remove the skin from the duck legs and discard. Shred the duck meat into long strips.
7) Add the sweet potatoes, shredded duck and chicken stock to the pan and warm over medium heat, adding more stock as necessary. Stir in the hoisin and chilli sauces, and season, to taste.
8) Remove from the heat and stir in the chopped parsley and sherry vinegar. Spoon 1 heaped tbsp of the duck hash onto a baguette slice and serve.