Step 1

In a saucepan, whisk the flour and water together until the flour dissolves.

Step 2

Place the saucepan over medium heat and stir the mixture frequently. In about 30 seconds to a minute, the flour will start to thicken. Stir constantly until the watery liquid absorbs into the paste. Turn off the heat and transfer the tangzhong to a bowl to cool. (See note 5 for microwave tangzhong directions.)

Step 3

Lightly grease a large mixing bowl with oil. Set it aside.

Step 4

In a microwave-safe bowl, heat the milk in the microwave on high for about 30 to 40 seconds. Use a thermometer to check the temperature of the milk. It should be somewhere around 105ºF to 120ºF. If the milk isn’t hot enough yet, heat it again for 5 to 10 seconds. If the milk is too hot, quickly whisk the milk and let it cool for several minutes.

Step 5

Add the sugar and yeast to the milk. Stir to hydrate the yeast. Let it sit for 5 to 8 minutes while you prepare the other ingredients. After 5 to 8 minutes, you should see a layer of foam on the top at least 1/4 inch thick (an indication that the yeast is active).

Step 6

In the bowl of a stand mixer, combine the all-purpose flour and salt. Add the melted butter, condensed milk, egg, tangzhong, and foamy milk/yeast mixture.

Step 7

Fit the mixer with the dough hook. Mix the dough on low until you don’t see any loose flour on the sides of the bowl. This should take 30 seconds to 1 minute. Then, increase the speed to medium-low and work the dough for 8 minutes. You may need to scrape down the sides of the bowl occasionally.

Step 8

Scrape the dough out of the bowl onto a lightly floured surface and knead a few times. If the dough is feeling tacky, lightly dust your hands with flour.

Step 9

Shape the dough into a ball and place inside the greased mixing bowl. Cover the bowl with a damp towel (or a silicone lid) and let it rise in a warm place for about 1 hour, until the dough doubles in size.

Step 10

About 15 minutes before rolling out the dough, make the filling. Measure out 2 1/2 tablespoons of sesame oil. In a bowl, mix the oil, scallions, pork floss, and salt. Make sure you still have 1 tablespoon of sesame oil left for the dough later on. Set the filling aside.

Step 11

Grease the Lodge Cast Iron Casserole Pan generously with butter. Set the pan aside.

Step 12

Punch down the dough to release excess air. Turn the dough over a lightly floured surface and knead the dough a few times so that the bottom is smooth.

Step 13

Roll out the dough to a 16x10-inch rectangle.

Step 14

Scoop out about 1/3 of the filling and spread it over the dough. Using a spatula or your hands, gently press the filling down on the dough. This helps to keep the filling in place for the next step.

Step 15

Make an envelope fold. Grab onto one short end of the rectangle and then fold a third of the dough towards the center. Then, take the other short end, and fold it towards the center so that you now have 3 overlapping layers of dough.

Step 16

Turn the dough over 90 degrees and roll out the dough until it is 17 to 18 inches long and 10 to 11 inches wide.

Step 17

Spread the remaining tablespoon of sesame oil over the dough and sprinkle 1/2 teaspoon kosher salt over the dough. Then, spread all the remaining filling over the dough.

Step 18

Grab onto a long edge of the dough and roll up the dough into a log. As you roll up the dough, make sure the sides are rolling up straight and not caving in. That helps to ensure that the rolled up dough is evenly thick throughout. I like to stretch the dough on the sides gently to ensure that the dough log is rolling up straight. Once rolled up, the dough log will be between 19 to 20 inches long.

Step 19

Slice the log into 12 equal pieces. I like using a sharp serrated bread knife for this. You can also use something like dental floss to cut the dough (see note 6 for more info).

Step 20

Place the rolls cut side down inside the greased Casserole Pan. Cover the rolls with a damp towel or plastic wrap, and let the rolls rise for 45 minutes to 1 hour, until they double in size.

Step 21

Preheat the oven to 375ºF and arrange an oven rack to the lower third position.

Step 22

Make the egg wash by whisking an egg with 1 tablespoon of water or milk. Brush a thin layer of egg wash over the rolls. Sprinkle several pinches of sesame seeds over the rolls. Then, sprinkle several pinches of pork floss over the rolls.

Step 23

Bake the rolls for 27 to 30 minutes, until the tops of the rolls are lightly golden brown. Let the scallion and pork floss rolls cool in the pan for 15 minutes before serving or transferring them to a cooling rack to cool some more.

Step 24

Store any remaining rolls in an airtight container at room temperature. They will keep for several days. To reheat, microwave the rolls on high heat for 15 seconds.