Har Gau (shrimp Dumplings)

Mix 3-1/2 cups flour, sugar and yeast in a large bowl. In a small bowl, combine milk and water. Add milk mixture to flour and stir until flour clumps. Turn dough onto lightly floured surface and knead for 10 minutes or until dough is smooth and elastic. Let rest for 15 minutes. Knead lightly for 1 minute. Place dough in lightly greased large bowl to rise till doubled about 30-45 minutes. Drop pork fat into 1-1/2 cups boiling water and allow to boil until it cooks fully and becomes translucent. Remove from the water, place in bowl, run cold water over it, let stand for several minutes, remove from water, dry with paper towel, and dice. Place shrimp in an electric mixer. With mixer running add salt, sugar, egg white, tapioca flour, oyster sauce, sesame oil, and white pepper. Add the cooked pork fat, water chestnuts, scallions, and bamboo shoots. Combine evenly and thoroughly. Place in a shallow bowl and refrigerate for 4 hours or freeze 25 minutes. When dough is doubled, punch down. Turn onto lightly floured surface and knead for 5 minutes. Split dough into quarters. Roll each quarter into 3" long cylinder. Split each cylinder into 6 pieces. Flatten and stretch pieces to 3-1/2 to 4" circles. Place a teaspoon of filling in the center. Fold the skin in half, forming a crescent or half-moon shape. Press to seal the edges. Steam 5 to 7 minutes, serve immediately.