Whisk the ingredients together in a small saucepan.

Place the saucepan over low heat.

Keep whisking until the ingredients form a thick paste. The consistency should be thick enough so that as you whisk the mixture, the whisk leaves lines in the mixture which remains.

Remove the paste to a small bowl, and set it aside to cool down.

Measure the flour, yeast, salt and sugar into the bowl of an electric stand mixer.

Mix the dry ingredients together using a dough hook.

Add the egg, cooled Tangzhong and pumpkin purée.

Once everything is combined, add enough milk for the mixture to come together in a sticky dough.

Add the butter, one tablespoon at a time. Wait for each tablespoon of butter to be fully incorporated into the dough before adding the next.

Continue kneading the dough on medium speed for about 10-15 minutes, or until the dough passes the windowpane test. (See Kitchen Notes below). By this stage, the dough should also be coming away from the sides of the bowl.

Lightly oil a large, clean mixing bowl.

Roll the dough into a smooth ball and place it into the mixing bowl.

Cover the dough with a clean tea towel or bowl cover, and place it somewhere warm for about 1.5 hours, or until it has doubled in size.

Gently remove the dough from the bowl. The dough will deflate as you handle it.

Divide the dough into 9 equal portions. Use a digital scale for even-sized buns.

Line a square baking pan with baking paper.

Roll each piece of dough into a smooth ball. I do this by pulling the edges of the dough into the centre, and then pinching those edges together while shaping the dough into a smooth ball as you do so. The pinched edges form the bottom of the buns.

Repeat the above steps with the remaining pieces of dough.

Place the shaped buns into the lined baking pan.

Cut 9 pieces of kitchen string measuring 80 cm in length.

Fill a small bowl with some vegetable oil.

Dip one piece of string into the oil, and then blot it between some sheets of kitchen paper.

Lay the string in front of you horizontally.

Place a piece of dough in the middle of the string (the top of the dough should be facing up).

Bring the pieces of string together to loosely tie a knot in the centre of the dough.

Then angle the strings, flip the dough over, and loosely tie a knot on the other side. 

To make buns with 8 segments, tie a knot at 4 cross-sections. To make buns with 6 segments, tie a knot at 3 cross-sections.

Cut off the excess string (they will otherwise stick to the bun during baking).

Repeat with the remaining pieces of dough.

Place the pan somewhere warm, covered with a clean tea towel, for about 30 minutes, or until the buns have puffed up slightly.

Preheat the oven to 180°C/356°F (without fan).

Place a metal baking tray on the middle shelf.

Lightly brush the buns with some milk.

Bake the buns for about 20-25 minutes, or until they are lightly golden. Check the buns at about 10-15 minutes and, if they are browning too quickly, cover the buns with a loose sheet of foil for the remaining baking time.

The buns are cooked if an internal thermometer reads 85°C/185°F.

Leave the buns on the pan for about 5 minutes, before carefully removing the buns to a wire rack to cool completely.

While the buns are still warm, cut off the strings and gently remove peel them away from the buns.

Decorate the buns with a pumpkin seed or similar.