Directions

1. Make the tangzhong. Cook 10g bread flour and 50g milk over medium heat, stirring constantly until the mixture forms a thick paste. Remove from heat and set aside to cool.
2. Combine the bread flour, whole wheat flour, sugar, salt, and yeast in a large mixing bowl.
3. Lightly beat 1 large egg. Add 30g to the dry ingredients and set aside the rest to use as a egg wash.
4. Add the cooled tangzhong and milk and mix everything together until it forms a rough dough. Use your hands to do this if necessary – the dough will be very sticky.
5. Transfer the dough onto a lightly floured surface and knead for 10 – 15 minutes, until the dough no longer sticks (it will still feel slightly tacky). Try to keep the same side of the dough facing down to prevent it from sticking to the surface.
6. At this point the dough may feel tough and will appear a little lumpy – don’t worry! Gradually knead in the 20g of butter until butter streaks are no longer visible. Continue kneading for ~10 more minutes until the dough becomes soft, clean and smooth.
7. Transfer dough to a lightly greased bowl, cover and let rise in a warm place for ~1 hour, until doubled in size.
8. Gently deflate the dough and divide into thirds. Give each third a quick knead then roll out into a rectangle. Fold the top and bottom towards the centre like a letter. Then roll along the long edge into a log, making sure to pinch the edge closed.
9. Place the thirds, seam side down, in a lightly greased 4.5 x 8.5 inch loaf pan. Cover and let rise for ~45 minutes until dough is ~1 inch over the top of the pan. At the 30 minute mark, preheat the oven to 350F.
10. Lightly brush the top of the dough with a thin layer of egg wash, then sprinkle with flaky sea salt. Bake at 350F for 30 minutes.
11. Remove from oven and immediately tip out of loaf pan. Gently tap the bottom of the loaf – it should sound slightly hollow. Let the loaf cool for ~30 minutes until the top is soft before slicing.