Instructions

1. For Stock - Preheat the oven to 425 degrees F. Place the chicken carcasses on a baking sheet and roast until golden brown.
2. Place the roasted bones, along with all of the remaining ingredients except the salt, in a large stockpot. Cover the pot and bring the water to a boil. Ladle a little hot liquid onto the baking sheet and use a wooden spoon to scrape up any browned bits, then pour it back into the pot. Lower the heat and allow the moisture to simmer for at least 6 hours and up to 12. Occasionally skim off the foam and scum that rises to the surface and discard it.
3. Remove the largest pieces of bone and vegetable with tongs and discard. Strain the stock through a fine-mesh sieve. Stir in salt to taste. Allow the stock to cool slightly, then refrigerate or freeze until needed.
4. For Dough - To make the dough, pour the water into a large mixing bowl and sprinkle in the yeast and sugar. Let the mixture stand for 5 minutes, then add the salt, 2 tablespoons of the vegetable oil, and 2 cups of the flour. Stir with a wooden spoon until the dough is homogenous, then add the remaining 1 cup of flour. Stir in the flour as best you can, then turn out the dough onto a clean work surface and knead it until it is completely smooth and elastic, 12 to 15 minutes. Alternatively, place the dough in the bowl of a stand mixer fitted with the dough hook attachment and knead on low speed for 7 to 8 minutes.
5. Pour the remaining 2 teaspoons oil into the bowl in which you mixed the dough. Place the dough ball in the bowl, turning it to coat all sides with oil. Cover the bowl with a clean kitchen towel and leave it in a warm place. Let the dough rise until it has doubled in size, 45 minutes to 1 hour.
6. Punch down the dough and turn it out onto a lightly floured work surface. Sprinkle the baking powder over the dough and knead it in until it is fully incorporated. Let the dough rest for 20 minutes while you prepare the filling.
7. For Filling - To make the filling, heat the oil in a large skillet over medium heat. Add the ground beef and cook until lightly browned, breaking up the chunks with a spatula or wooden spoon. Remove the pan from the heat and scoop out the beef, leaving any rendered fat behind. Pour out all but 1 tablespoon of fat, return the skillet to medium heat, and add the onion and bell pepper. Cook until softened, 8 to 10 minutes. Add the garlic and ginger and cook, stirring, for 2 more minutes.
8. Return the beef to the skillet and stir in the currants, cumin, cinnamon, crushed red pepper, salt, vinegar, and stock. Bring the mixture to a simmer and cook for about 10 minutes. Remove from the heat and stir in the cilantro. Let the mixture cool before assembling the buns.
9. Working on a lightly floured surface, divide the dough into 16 equal pieces and roll them into balls. Cut sixteen 3-inch squares from parchment paper. These will be placed underneath the buns so they don't stick during the steaming process. Roll out each dough ball into a circle 4 inches in diameter. Place the dough circle in the palm of your hand and spoon 2 tablespoons of the filling into the center. Gather the edges of the circle up around the meat mixture, pinching the top closed. Place the bun on a parchment square, pinched side up.
10. Heat about 3 cups of water in a large steamer. Place the buns in the steamer about 1 inch apart so they don't stick together, and steam for 25 minutes. Serve hot.