Cut the duck into pieces the day before, and put them into a large bowl with the salt, pepper, oil, vanilla, mushrooms and wine. Leave to sit overnight. The next day, drain the pieces of duck and reserve the marinade.
Fry the duck pieces in a large pan.
Thinly slice the tomatoes and onions, and pound the garlic and ginger together. Add the onions once the duck is browned. Stir for two minutes, then add the garlic, ginger, tomatoes and stir. Add the marinade and turmeric.