1. In a small saucepan, whisk together 3 tablespoons bread flour, 1/2 cup milk, and 1/2 cup water until smooth. Heat over medium-low, stirring constantly until thickened into a paste. Let it cool to room temperature.

2. In a stand mixer bowl, combine 2 1/2 cups bread flour, 3 tablespoons sugar, 2 teaspoons instant yeast, and 1 teaspoon salt. Add the tangzhong, 1/2 cup lukewarm milk, and 1 large egg. Mix with dough hook until combined.

3. Add 1/4 cup softened butter and knead for 10–15 minutes until the dough is smooth and elastic.

4. Transfer dough to a greased bowl, cover, and proof for 1 to 1.5 hours until doubled in size.

5. Punch down the dough, divide into 3 portions, and let rest for 10 minutes. Roll each into a log and place into a greased loaf pan.

6. Let it rise again for 40–50 minutes, until it reaches the top of the pan.

7. Preheat oven to 350°F (175°C). Mix 1 egg yolk and 1 tablespoon milk, then brush over the top.

8. Bake for 30–35 minutes until golden brown and internal temp reaches 190°F (88°C). Tent with foil if browning too fast.

9. Let cool in the pan for 10 minutes, then transfer to a wire rack to cool completely before slicing.