Cut the red chillies and soak them in water for about two hours. Cut up into small pieces and soak in the vinegar for one to two hours. Put all the ingredients in a mixie and grind to a smooth paste.
Prepare Momos:
In a bowl mix all the ingredients of the chicken or vegetable filling, according to your choice. Keep aside.
Knead the refined flour, baking powder and salt together into firm dough. Cover and keep aside for 30 minutes.
Roll the dough into very thin 4-5 inch rounds.
Take each round piece and place some filling in the center.
Bring the edges together and twist to seal it.
Steam in a steamer for about 10 minutes and serve hot with chili sauce.