• Open the tube of refrigerated biscuits and separate each dough. With hands or a rolling pin, flatten dough to about 3-inch diameter.
• Place a meatball and an egg on center of each flattened dough and pull edges to center. With hands, twist edges to fully enclose filling.
• Place each dough balls seam side down on 3 x 3-inch cut parchment paper and arrange in a single layer on a steamer basket at about 1 to 2 inches apart.
• In bottom part of steamer, add water and 1 tablespoon of vinegar for every liter of water.
• Place the steamer basket over the pot of water, cover, and steam for about 10 to 15 minutes or until buns are puffed and tops are shiny. Remove from steamer and serve hot with sauce.

For the Sauce

• In a saucepan, combine water, sugar, soy sauce, cornstarch, oil, and salt to taste, Stir until sugar and corn starch are dissolved.
• Over medium heat, bring to a boil. Continue to cook, whisking regularly to prevent lumps, for about 2 to 4 minutes or until thickened.