1. Put the high-gluten flour in a basin, mix well, dig a small pit in the flour, pour water and egg liquid and stir into a dough, knead until the dough is smooth, add butter and knead until the expansion stage, cover with plastic wrap and ferment for about 60 minute.
2. Prove to 2 to 2.5 times the volume of the dough.
3. Take out the dough and divide it into several equal parts, round it, cover with plastic wrap and relax for 10 minutes.
4. Use your hands to roll the dough into a rod with a wide top and a narrow bottom.
5. Roll it out with a rolling pin, about 30 cm long. Roll up from the wide end.
6. After rolling, put the end down in the baking tray, cover with plastic wrap and ferment again for about 30 minutes.
7. When the volume becomes 1.5 to 2 times, the surface is evenly brushed with egg liquid. Preheat the oven to 200 degrees and bake for about 13 minutes.
