2. Take the oil pan and fry the shredded mushrooms. Put the fat part of minced meat into a wok and stir fry, then add soy sauce and stir fry. Before turning off the fire, add the fried onion crisp and mix well. After a little cooling, add the remaining two pieces of minced meat and white pepper and mix well to make stuffing. Divide the yolk into 4 parts and soak the dried yeast in 3/4 glass of water for about 3 minutes. Mix medium-gluten flour, yeast water and fine sugar, beat into dough, and add a spoonful of oil to make smooth dough.
3. Take out the dough and knead it into a ball, wrap it tightly in a plastic bag and put it in the refrigerator for one night.
4. Take out the refrigerated dough, knead it evenly again, squeeze out air, pull out a long strip from it, shape it, divide it into 12 pieces, and stick it into thin and medium-thick dough pieces.
5. Put the meat stuffing, then put an egg yolk block, wrap it into a birdcage steamed bun, put release paper at the bottom, and let it stand for 20 minutes for secondary fermentation.
6. Move into a steamer and steam for 20 minutes. Stew after flameout 1 min before opening the lid. Tear off the release paper while it is hot and put it on the shelf for ventilation and cooling.