1To make the Tangzhong, whisk and cook flour, milk, and water in a saucepan over medium heat until it becomes smooth and thick like pudding.
2Transfer the Tangzhong to a bowl, press plastic wrap against the surface, and let it cool to room temperature.
3In a separate bowl, mix warm milk with 1 teaspoon of sugar and 1 packet of yeast, and let it sit for about 5-10 minutes until frothy.
4Add the cooled Tangzhong, egg, sugar, flour, and salt to the yeast mixture. Mix until a shaggy dough forms.
5Knead the dough in a stand mixer with a dough hook for about 5 minutes, then add in the melted butter. Knead for another 5 minutes until the dough is smooth and no longer sticky.
6Lightly coat the dough with flour, shape it into a nice ball, and place it in a bowl. Cover with plastic wrap and let it proof for 1-2 hours until doubled in size.
7After the first proof, punch down the dough and divide it into 9 pieces. Shape each piece into a small ball and place them in a greased or parchment-lined square pan.
8Cover the pan with plastic wrap and let the dough balls proof a second time until doubled in size (about another hour).
9Preheat the oven to 350°F. Brush the tops of the rolls with an egg wash.
10Bake the rolls for about 20 minutes, tenting with foil if they start browning too quickly.
11Once out of the oven, brush the warm rolls with melted butter and sprinkle with sea salt.
The Tangzhong method, which involves gelatinizing starch in flour, allows more moisture to be absorbed into the dough, resulting in softer and fluffier bread.
When your bread goes stale, it's because moisture leaves the bread and it gets hard.