1. Put the dough ingredients except butter in the cook machine and beat until the gluten is expanded and the surface is smooth.
2. Add butter and beat until the expansion stage. (This state in the picture is actually a complete stage)
3. Put the beaten dough into a basin, cover it with plastic wrap, and place it in a warm place for basic fermentation to 2.5 times its original size.
4. Divide the fermented dough into 7 equal parts. After rounding, cover with plastic wrap and relax for 15 minutes.
5. Roll out the loose dough, pack 65 grams of purple potato mash, and seal it.
6. Seal the dough upward and roll it into a tongue shape. Use a sharp knife to make 4 openings on the dough.
7. Fix the dough with your left hand and rub inward with your right hand to roll up the dough.
8. Place the two ends in a paper bread cup.
9. After everything is done, put it in a baking tray and place it in a warm and humid place for the final fermentation; at the end of the fermentation, the surface is brushed with egg liquid.
10. Preheat the oven at 180℃, the middle layer, and bake for about 25 minutes; after it is out of the oven, it is placed on the grill to cool.
Tips:The liquid is adjusted according to the state of the dough, I actually used 110 grams of milk.
