牛肉洋葱大包子，鲜嫩多汁关键在于调馅儿，个个皮薄馅儿大

牛肉馅儿 Filling：可以做500g面粉的包子 400g Ground beef 牛肉末 2tsp Soy sauce 生抽 2tsp Dark Soy sauce 老抽 1tsp Oyster sauce 蚝油 1/8tsp Sichuan pepper powder 花椒粉 1/8tsp White pepper powder 胡椒粉 1tsp Salt 盐 100ml Ginger /green onion water 葱姜水 2tbsp Oil 自制香油/油 1 pcs Onion 洋葱 包子皮Buns skin： 250g All purpose flour 中筋面粉 2 cup+1/2 cup 125ml Warm water 温水 3g Yeast 酵母 1 tsp 10g Sugar 糖 3/4 tbsp 10g Oil 油 3/4 tbsp