Black Sesame Filling

1. Toast black sesame seed in a pan over medium heat. Keep stirring until you smell the aroma and hear light popping sound. Transfer to another pan or plate to cool.
2. Using a coffee grinder, blender, or food processor, grind the toasted seed until smooth. Add sugar and melted butter, mix until even. Transfer the filling to the refrigerator and chill for 1 hour.
3. Divide the chilled sesame filling into 10 equal portions and shape them into balls. Set aside.

Bun Dough

1. Stand Mixer: In a large mixing bowl, combine milk, yeast, sugar, flour, and oil. Using dough hook attachment, mix on low speed for 5 minutes, then increase to mediums speed and mix for another 5 minutes. Mix until the dough is white and smooth.

   Kneading by Hand: Mix yeast and sugar with milk. Stir in flour and mix. Then add oil and start kneading. Use one hand to push the dough then pull it back. Alternating hands, repeat this motion for 8-10 minutes, until the dough is smooth and shiny in appearance. (You should be sweating by then!)

2. Take the dough and divide into 10 equal portions (50 g each). Cover with plastic wrap or towel to prevent them from drying.
3. Roll each piece of dough into a log. Then take both ends and fold toward the middle. Press down with the palm of your hand. Repeat this two more times to get rid of air bubbles.
   
4. To ensure that the bun has a smooth surface, use your palm to fold the edge toward the middle (2). Gently press down in the middle. Then slightly rotate and do it a few more times, until all edges are nice and round with no cracks or lines. If you turn the dough upside down, the top will look very smooth (4), and the bottom will look like belly button (3).

   With the belly button side facing you, flatten the dough ball again using your palm (5). Use a rolling pin to roll the ball into a round disc that is thick in the middle and thin on the edges (6).
   

Assembly

1. Place sesame filling onto the center of the disc. Press the sesame with your thumb and use your other hand to gather the wrapper onto the top of the filling. The dough sheet will start to form pleats and retain its round shape. Place the assembled bun, pleated side down, onto a cut out parchment sheet or a lined steamer. Cover it while you repeat the same process with the remaining dough.
   
2. Rest the buns in room temperature for about 30 minutes before steaming. The bun should rise to at least 1.5 to 2 times its original size.

Steaming

1. Prepare the steamer and steam for about 10-12 minutes. Turn off heat and let it rest for 5-10 minutes. Open the lid very carefully and make sure water does not drip onto the buns. Transfer onto a cooling plate. Enjoy!

Storage and Reheating

1. Black Sesame Steamed Buns taste BEST when they are warm and fluffy. If you are not eating on the same day, you can store them in an air tight container in the fridge and microwave for 30 seconds before serving.