Chinese BBQ Pork Buns

Name: Chinese BBQ Pork Buns
Ingredients: FOR THE BUNS:; 5 cups Bread Flour Or All Purpose Flour, Plus 1/3 Cup; ⅔ cups Water; 1-⅓ cup Milk, Divided; ⅓ cups Sugar; 1 teaspoon Salt; 4 teaspoons Instant Yeast; 2 whole Eggs; 4 Tablespoons Butter, Melted; 1 whole Egg (beaten With Below Amount Of Milk To Make An Egg Wash); 1 Tablespoon Milk; 1 Tablespoon Sesame Seeds (optional); FOR THE FILLING:; 2 Tablespoons Canola Oil; ½ cups Finely Chopped Shallots Or Onion; 2 Tablespoons Sugar; 1-½ Tablespoon Soy Sauce; 2 Tablespoons Oyster Sauce; 1-½ Tablespoon Sesame Oil; 1 Tablespoon Dark Soy Sauce; ¾ cups Chicken Stock; 3 Tablespoons Flour; 2 cups Diced Chinese Roast Pork (plain Roast Pork Will Also Work)