• Sift and place flour, instant yeast, baking powder, cornstarch, and sugar in a bowl of an electric mixer fitted with the bread hook attachment. Add the water and vegetable oil and mix for 7-10 minutes on medium speed, until a smooth dough forms.

  If the dough is too dry, add ½ - 1 tbsp. of water. If it's too sticky, add 1 tbsp. of flour.
• Form dough into a ball and place in a glass bowl. Cover with cling film and allow the dough to proof in a warm place for at least 90 minutes, or until it doubles in size.
• Place dough on a clean, lightly floured surface, and punch it down. Roll out the dough to 4mm (¼ inch) thickness. Use a round 9-11cm (3.5-4.5") cookie cutter or the rim of a drinking glass to cut out circles (6-10, depending on cutter size).
• Use a pastry brush and some vegetable oil to lightly brush the surface of each dough piece. Place a chopstick at the centre of each cricle and carefully fold the dough in half (to create a semi-circle). Pull out the chopstick.
• Place each bun onto a small piece of parchment paper, and transfer to a baking sheet (or a large flat plate). Cover the baking sheet with a tea towel and allow the buns to proof for another 30-40 minutes, until "puffed up" and doubled in size.
• Steaming using electric steamer: Place the buns with parchment paper into a heated steamer. Steam for 8-12 minutes until the buns have puffed up and fluffy.

  Steaming using bamboo steamer: Fill a large pan or wok with some water. There should be enough water to submerge the bottom part of your steamer, but not too much water that it touches the food at the bottom when it bubbles.

  Bring water to a slow boil. Once water is bubbling, place the buns on parchment paper in the steamer (you may use multiple levels). Cover and steam for 7-8 minutes, adding more water to the pan if it starts to dry out.
• Transfer buns to serving plate using kitchen tongs, allow to cool slightly, then fill up with your favourite filling and serve warm!

Filling

• In a large skillet, heat sesame oil. Add diced aubergine, zucchini, and orange/red pepper and saute until cooked through.
• In a medium-sized bowl, mix sauce ingredients. Pour in skillet with vegetables and stir to coat well. Simmer for 2-3 minutes until some liquid dissolves and sauce thickens.
• Fill bao buns with vegetable filling and top with julienned carrots, parsley leaves, and seseame seeds.