First, make the filling. In a small bowl, add the curry powder. Add enough water to make a runny paste. Set aside.

In a large pot or wok over medium high heat, heat the oil. Add the onions and garlic and cook, stirring, until softened, 2 to 3 minutes.

When the onions are soft, add the curry leaves and cook, stirring, until fragrant, 1 to 2 minutes.

Add the curry powder paste and cook, stirring, until all the liquid has evaporated and the oil separates.

Pour in ½ cup water and cook, stirring, until again the liquid has evaporated and the oil separates. Repeat this step once more.

Add the minced chicken and cook, stirring, until thoroughly combined.

Season with the black pepper and chicken stock powder.

Add the potatoes to the pan, and stir to combine.

Sprinkle the brown sugar and the seasoning powder. Adjust seasoning to taste.

Add ½ cup water, and stir to combine. Turn down the heat to medium low and cook, covered, stirring occasionally to prevent the bottom from burning, 25 minutes.

At this point, the potatoes should be tender. Remove the cover and cook off any remaining moisture, another 5 minutes.

Stir in the chopped celery leaves. Turn off the heat.

Transfer the mixture into a large tray, and spread into a thin, even layer. Let cool.

Once the filling has cooled, divide into 16 portions.

Make the pau dough. In your stand mixer bowl, add the water or milk, cooking oil, sugar, vanilla essence if using, and yeast.

Add the flours, salt and baking powder.

Knead at the lowest speed on your mixer until a shaggy dough forms, then increase the speed one step and continue kneading, about 14 to 15 minutes.

Shape into a round ball and let rest in your mixing bowl, placed in a warm place and covered with a damp cloth, 15 minutes.

Transfer the dough to a floured surface.

Divide the dough into 16 pieces. Each piece should weigh around 55 to 57 grams.

Shape each piece of dough into a ball. Keep the dough covered to prevent them from drying out.

Prepare 16 pieces of greaseproof paper or reusable silicone baking sheets, about 8cm by 8cm square. Arrange them in your steamer basket, leaving some space in between.

Working with one piece of dough at a time and keeping the rest covered, flatten the dough with the palm of your hand.

Using a floured rolling pin, roll the dough into a ¼-inch thick disc.

Place your rolling pin on about ⅓ of the disc from the top. Roll outwards. Turn the disc about a quarter turn, and repeat. Repeat until you have a disc with a thinner outer ring but still about ¼-inch thick in the centre.

Assemble the pau. Scoop a portion of the filling onto the center of the disc.

Place on your prepared paper squares in the steamer basket. Repeat for the remaining dough. Let rest, covered, about 45 minutes.

Before steaming the buns, lightly spray them with water.

Wrap the lid of your steamer with a large cloth or towel. This is to prevent the condensation from dripping onto the buns.

Place the basket over your steamer, cover tightly with the lid and steam, 15 minutes.

Do not open the lid and let the buns rest undisturbed for about 10 minutes after turning off the heat. This will prevent them from collapsing. If you are unable to steam all the buns in one go, place the remaining buns in the fridge, covered, until they are ready for steaming.

Serve warm.