Hi Karen I don't have the recipe for Chan Bao. Here is a recipe using yeast. The recipe is for steaming. I am sure you can bake it with egg wash glaze on top.

STEAMED BUNS WITH ROAST PORK FILLING

What's important is the filling should be small to stuff in the buns and the sauce should be thickened with cornstarch and water.

Roast Pork Filling
Makes about 2-1/2 cups

2 tablespoons cornstarch
6 tablespoons water
1 tablespoon oil
1 cup chopped onions
2 cups coarsely chopped roast pork
2 tablespoons light soy sauce
1 tablespoon sugar
pinch salt and white pepper
1/4 cup chopped scallions

Stir together cornstarch and 4 tablespoons water and set aside. Heat oil in wok and saute onions until clear. Stir in pork, the remaining 2 tablespoons of water, soy sauce, sugar, salt, and pepper. Push pork to the side of the wok, add the cornstarch mixture to the center, and stir that until thickened. Then combine the pork with the mixture and then put in the scallions. Remove from heat and set aside until it cools to room temperature. You can also refrigerate this and let it come to room temperature when you're ready to stuff the buns.

STEAMED BUNS:
Makes 14

3/4 cup warm water (105-115*F.)
1 package dry yeast
2 teaspoons sugar
2 tablespoons corn oil
2-1/2 cups unbleached all-purpose flour
filling at room temperature

In a measuring cup, combine water and yeast. Stir until dissolved and let it stand until it gets foamy, about 1 minute. Add sugar and oil and mix well.

Place flour in food processor fitted with metal blade. While blade is running, add the liquid slowly and process until a ball forms. If a ball doesn't form, add water 1 tablespoon at a time until it does. Continue to process another minute until dough is very smooth and does not stick to the fingers.

Roll the dough into a cylinder and cut into 14 even pieces. Lightly roll each piece into a 3" round and carefully stuff them with the filling.

Bring dough around from all sides and twist to seal.

Put each bun seam-side down on a piece of parchment or wax paper. Let rise in a warm place (about 80 degrees F.) for 30 minutes or until doubled in size. Steam in a bamboo steamer over high heat for about 15 minutes. (You could probably bake them for about 15 minutes at 350 F.)

In a plastic bag, they will keep for about three days in the fridge or up to two months in the freezer.