The dough. In a small bowl, dissolve the yeast and sugar in the warm water. Set aside for 5 minutes, until the yeast is activated. It should become foamy. Add 2 tablespoons olive oil to the yeast mixture and set aside.
In a large bowl, combine the flour and salt together, Pour the yeast mixture into the flour and salt mixture and mix until you get the dough. Place the dough onto a lightly floured surface and knead for 5 minutes, until it is smooth. When ready, place inside a lightly oiled bowl. Cover with plastic wrap and allow the dough to rest for 1 hour.
The filling. Heat 1 tablespoon olive oil in a skillet. Add the garlic, tomato, green onions, and cook for 2 minutes, until the tomato softens. Add the curry powder, chicken, coconut milk, chicken stock, and soy sauce. Cover and simmer for 10 minutes, until the chicken is cooked. Uncover and cook for 5 minutes more, over high heat, until the sauce thickens. Remove from heat and stir in the lime juice and cilantro. Season with fresh ground black pepper to taste. Let the filling cool for 5-10 minutes.
The buns. Punch the dough down to release the air. Place it onto a lightly floured surface and roll into a log. It should be about 12-inch (30cm) long. Divide the dough into 10 pieces. Work with one piece at a time covering other pieces so they don't become dry. Take one piece of the dough and flatten it with the palm of your hand into a 6-inch (15cm) circle (approximately). Place 2 tablespoons of the filling in the center of the circle and draw up the sides together at the top of the bun. Pinch and twist the top to seal it. Place the bun on a little square (3x3 inch or 7x7cm) of parchment paper. Continue with the remaining buns.
Cook the buns in a steamer for 12-15 minutes. Enjoy!